Ukrainian President Volodymyr Zelenskyy welcomed the U.S.-brokered “energy ceasefire” but warned Monday that Kyiv would retaliate if Moscow failed to comply, as fresh Russian drone attacks targeted Ukraine’s energy infrastructure just hours after President Donald Trump announced the agreement.

“It is increasingly evident that Russia is unwilling to accept an energy ceasefire proposed by the United States and intends to continue its terrorist air attacks against our people and communities,” Zelenskyy said Monday in a post on X. “Today alone, the Russians have attacked 6 energy facilities in Ukraine.”

Speaking earlier in the day via video link at the Warsaw Security Forum, he said Ukraine was prepared to sign guarantees if the U.S. required them to build trust, stressing the importance of a shared understanding of the situation. “If Russia does not agree to an energy ceasefire, we will respond,” he cautioned.

“All morning today, more and more Russian jet-powered shaheds have continued to enter our skies over Kyiv and other Ukrainian cities. We shoot down many of them, and if we didn’t, there would clearly be even more damage to our energy infrastructure,” he said.

“For now, this is Putin’s answer to Trump.”

It comes after Zelenskyy lamented Russia’s continued drone attacks on Ukrainian energy targets on Sunday, including an attack on a power plant in Kharkiv in Eastern Ukraine close to the Russian border.

Overnight, Russia attacked state-owned Ukrainian energy company Naftogaz’s gas production infrastructure in Kharkiv region, the company said. No one was injured in the strike by the jet-powered drone, which caused a fire at the facility, it added.

Naftogaz’s acting CEO, Sergii Fedorenko, said the attack had damaged critical equipment and that employees were working to repair damage as quickly as possible and prevent any risks to operations of the energy system.

Earlier on Sunday, Trump announced an “energy ceasefire” to lower fuel costs ahead of the U.S. midterm elections.

“Effective immediately, there is an ENERGY CEASEFIRE in the War between Russia and Ukraine. Both parties have agreed. Do not break it!” Trump wrote on social media on Sunday.

The Kremlin said on Monday that contacts are ongoing on an energy ceasefire and that it would provide more information in due course, Reuters reported. It declined to comment on whether any deal would be limited to oil refineries. Russia’s presidential office didn’t immediately respond to a CNBC request for further information.

Since Russia’s full-scale invasion of Ukraine in 2022, ceasefires have repeatedly proved fragile. Trump has tried several times to broker an end to the war, but none have succeeded so far.

“We’ve been here many times before over the last four and a half years, so I don’t think we should build our hopes up too much,” former IEA head of oil Neil Atkinson told “Squawk Box Europe” on Monday.

Deal with Russia

On Friday, Trump said he had made a deal with President Vladimir Putin in which Russia would supply more than 4 million tons of diesel to global markets.

“The reality of it is that the volumes talked about are very small,” said Atkinson, who is also a visiting fellow at the National Center for Energy Analytics. “The deal that’s been agreed is not really market moving in any significant way.”

According to Trump, Russia will supply more than 300,000 tons of diesel immediately, followed by 500,000 tons in November, and then another 4 million tons of diesel based on the condition of Russia’s refineries.

EU top diplomat Kaja Kallas welcomed an energy ceasefire but said, “This is not the time to ease pressure on Russia.”

“Suspending sanctions on Russian diesel provides Moscow with more revenues to wage war,” she said in a statement Saturday.

EU’s foreign ministers are due to meet in Luxembourg on Monday morning to discuss the Russia-Ukraine war, among other things. The EU will adopt nearly 1,600 new sanctions listings targeting Russia’s military-industrial complex, in the single largest expansion of our sanctions list since Russia started its war, Kallas said ahead of the meeting.

Oil prices turned positive after Zelenskyy’s Monday comments, after trading about 1.5% lower earlier in the session.

Brent crude futures with December delivery were up 2% to $106.82 a barrel at 10:15 a.m. ET, while West Texas Intermediate futures for November ticked 1.9% higher to $93.60 per barrel.

Microsoft plans to increase deployment of its internally developed AI chips following years of depending on Nvidia’s GPUs, as the company seeks to strengthen its AI portfolio. Beginning with the newly unveiled third‑generation Maia AI accelerator, Microsoft stated it will primarily use its own silicon to process incoming requests.

Microsoft’s core AI advantage lies in its Azure cloud, which hosts numerous models for customers. Products such as Microsoft 365 Copilot and GitHub Copilot deliver AI‑driven capabilities to developers and office staff. The firm also creates proprietary models, though they have not yet gained significant traction in a market led by OpenAI, Anthropic and Google.

The chip opportunity arises from relentless demand for advanced processors and a market appetite for alternatives. Nvidia’s GPUs have long been the default for AI workloads, populating Microsoft’s data centers and also training models for OpenAI and Anthropic.

As demand continues to rise, AI leaders are diversifying their silicon sources, turning to offerings from Amazon, AMD, Cerebras, Google and, recently, Microsoft itself. For general‑purpose computing, Microsoft already uses its own CPUs alongside chips from Intel and AMD.

CFO Amy Hood noted at a Goldman Sachs conference last month that leveraging its own hardware has contributed to “margin improvement over the course of a decade.”

Microsoft launched its first AI chip, the Maia 100, in 2023. It highlighted the Maia 200 earlier this year, and CEO Satya Nadella told analysts in July that the Maia 200 provides “30% better performance per dollar than the latest generation hardware in our fleet” and is already running OpenAI models.

Mass production of the Maia 300 is slated for 2027. Microsoft aims for multi‑gigawatt rollouts of the Maia family, according to a blog post by Executive Vice President Scott Guthrie, though General Manager Alistair Speirs declined to give a firm timeline.

“We keep some flexibility because the sector evolves rapidly, and we want to match the right silicon to the right models at the right time,” Speirs remarked. Microsoft plans to fit 96 Maia 300 chips per data‑center rack—twice the count of the Maia 200.

The new chip can process up to seven times more AI tokens per rack and delivers 40% more tokens per megawatt compared with GPUs. “We need architectures that improve performance and power utilization,” Speirs said, adding that power efficiency translates directly into lower data‑center operating costs.

Jim Kleewein, a technical fellow, said portions of Microsoft 365 Copilot will run faster with the Maia 300.

In a Wednesday client note, Evercore ISI analysts projected that Maia will account for roughly 10% of Microsoft’s AI chip spending by Q1 2027 and advised buying the stock.

Nvidia will remain a major partner; CEO Jensen Huang spoke at an event last week where Microsoft unveiled a Surface laptop equipped with an Nvidia processor, and Speirs confirmed that Microsoft continues to collaborate with Nvidia and AMD on model training. Unlike Google’s TPUs or Amazon’s Inferentia and Trainium, Microsoft’s accelerators are not offered for hourly rental to external firms.

“No one has tested them outside Microsoft yet,” said Patrick Moorhead, CEO of Moor Insights and Strategy. WATCH: Melissa Otto: Nvidia is the bellwether of the AI trade

Saudi Arabia said Monday it was dealing with more drones and missile strikes as a slew of countries warned against travel to the kingdom due to fatal attacks on Riyadh’s airport by Iran-backed Houthi militants.

The Australian and New Zealand governments on Monday cautioned their citizens against traveling to King Khalid International Airport in Riyadh and other Saudi destinations, joining similar advisories from the U.K., U.S., Canada, France, Germany, Japan and others.

The Saudi aviation authority extended the suspension of operations at the airport, which has been hit by numerous projectiles over the past week. The deadliest strike came on Saturday, when 12 people were killed and more than 300 were injured, according to officials. Another strike on Sunday killed one person and injured nearly a dozen.

Yemen’s Iran-backed Houthi rebels have claimed responsibility for the attacks, which have raised questions over the robustness of Saudi Arabia’s defense capabilities despite its huge military spending.

The fatalities come as the kingdom hosts major corporate conferences, including the World Petroleum Congress, the International Energy Forum Ministerial Meeting and the Future Investment Initiative.

Airlines canceled hundreds of flights scheduled for the coming days, and about 100 flights were forced to divert to other airports, according to Flightradar24. The Federal Aviation Administration warned U.S. carriers of potential risks of flying over and around Saudi Arabia.

Delta Air Lines

U.S. President Donald Trump said Sunday that the U.S. “may” join Saudi Arabia in its retaliation against the Houthis.

Iran’s foreign minister, Abbas Araghchi, said Sunday that he had told Saudi Minister of Foreign Affairs Prince Faisal bin Farhan Al Saud by phone that Tehran was willing to take steps to start dialogue between Saudi Arabia and Yemen, where the Houthis are based.

Iranian Foreign Ministry spokesperson Esmail Baghaei meanwhile said Iran was still reviewing a U.S. response to its proposal for reopening the Strait of Hormuz and would reply through its intermediaries, Reuters reported.

— CNBC’s Leslie Josephs contributed to this report.