U.S. Secretary of State Marco Rubio said on Tuesday (May 26, 2026) that Washington remained ready to mediate in the war between Russia and Ukraine, after Moscow threatened new strikes on Kyiv.

Russia's warning, including a call for foreign diplomats to flee the Ukrainian capital, marks a fresh escalation in the more than four-year war, with Moscow vowing "systematic" attacks on Kyiv, including on "decision-making centres".

Mr. Rubio's offer came after Russia battered Ukraine over the weekend — including firing its Oreshnik hypersonic missile — and following a phone call with Russian Foreign Minister Sergei Lavrov.

"Every time you see these big strikes from one side or the other, it's a reminder of why this is a terrible war that's now gone on longer than the Second World War, and it needs to come to an end," Mr. Rubio told reporters during an official visit to India.

"The U.S. stands ready and prepared to help do whatever we can to help facilitate the end of this war, and hopefully the opportunity will present itself at some point," Mr. Rubio said.

An overnight Russian strike killed a 45-year-old man in Odesa, regional official Sergii Krasylenko said on Telegram early Tuesday (May 26, 2026). Russia's weekend barrage involving dozens of drones and missiles — killed four people and caused widespread damage across the Ukrainian capital.

Among the weapons Russia used was its Oreshnik hypersonic missile, which can travel 10 times the speed of sound and is capable of carrying nuclear warheads, according to Moscow. The strikes followed Russian accusations that Ukraine hit a vocational school in the Russian-occupied Lugansk region, killing 21 people. Russian President Vladimir Putin ordered his military to retaliate.

"Under the current circumstances, the Russian Armed Forces are starting to launch systematic strikes against Ukrainian military-industrial facilities in Kyiv," Russia's Foreign Ministry said in a statement. "The strikes will target both decision-making centres and command posts... We are warning foreign citizens, including personnel of diplomatic missions and international organisations, to leave the city as soon as possible," it added.

Mr. Lavrov relayed the warning to Mr. Rubio in a phone call on Monday (May 25, 2026), urging him to evacuate U.S. diplomats, Russia's Foreign Ministry said. When asked, Mr. Rubio told reporters on Tuesday (May 26, 2026) that Russia had "sent a notice to all the embassies", not just the U.S. mission.

'Not going anywhere'

Russia had already called on foreign citizens and diplomats to evacuate Kyiv earlier this month, when it threatened massive strikes on central Kyiv if Ukraine disrupted a military parade on Red Square.

Western diplomatic missions in the city have rebuffed both warnings. A spokesperson for France's Foreign Ministry said on Monday (May 25, 2026), "We're used to Putin's threats. It is out of the question to evacuate."

The European Union's Ambassador in Kyiv said on Facebook, "We are not going anywhere." Ukraine described Russia's threats as "rhetoric". "We are now telling our partners that they should not give in to all this Russian blackmail," Ukrainian Foreign Minister Andriy Sybiga said.

Russia launched its full-scale offensive on Ukraine in February 2022. The conflict has since spiralled into Europe's deadliest since World War II. U.S.-led talks on ending the fighting have stalled in recent months due to the conflict in the West Asia.