Ukrainian President Volodymyr Zelenskyy accused the United States of deliberately delaying the delivery of interceptor missiles to his war-torn country ahead of reported talks with a top US envoy on Tuesday.
Relations between Kyiv and Washington have soured over military aid and intelligence sharing, with Zelenskyy saying on Monday that Ukraine received no early warning of powerful Russian missile strikes that targeted energy facilities in the capital region.
US-led diplomatic efforts to end Europe's deadliest conflict since World War II have stalled in recent months, as Washington has shifted focus towards the war with Iran.
Zelenskyy told US senators on Monday that "the Pentagon is delaying the delivery of missiles" already paid for by European countries and that the shipment was waiting for US Defence Secretary Pete Hegseth's signature.
He said several European countries were ready to transfer Patriot interceptor missiles from their own stockpiles but were still awaiting US approval.
"The missiles are ready and they could already be in Ukraine," Zelenskyy said. "But unfortunately, there is still no approval."
The United States has denied making any changes to intelligence sharing with Ukraine.
Trump has also denied ordering a reduction in speeds on the US government-owned and -controlled Starshield network after Elon Musk, whose company SpaceX developed it, said the order could only have come from the White House.
Strained relations
A public rift erupted between Trump and Zelenskyy when the US leader partially lifted sanctions to strike a diesel-supply deal with Russian President Vladimir Putin.
Trump also slammed Zelenskyy as a warmonger for Ukrainian attacks on Russian oil refineries.
"Zelenskyy doesn't know what he's talking about," Trump said on Monday in another attack on his Ukrainian counterpart.
"To be honest, I think it's time for somebody else to negotiate on behalf of Ukraine."
Trump said he was ready to meet Putin and Chinese leader Xi Jinping in China next month to discuss denuclearisation, adding that talks could also cover the Ukraine war, fuelling fears in Kyiv that it was being sidelined.
Kremlin spokesman Dmitri Peskov confirmed earlier that "the topic of such a hypothetical has indeed been mentioned", when asked about a Wall Street Journal report on Sunday that Trump, Putin and Xi could meet.
Ukraine's Foreign Minister Andrii Sybiha said that such a meeting would "only encourage Putin to continue this war".
News outlet Axios reported that White House envoy Steve Witkoff was travelling to Oslo on Tuesday to meet Zelenskyy and European leaders and then to Russia to meet Putin.
Russian strikes
Zelenskyy also spoke to Pope Leo XIV on Monday, according to the Vatican, days after the Catholic leader held a similar call with Putin.
The Vatican said the pope had urged both sides to allow for the flow of aid into the Russian-occupied town of Oleshky and to let civilians leave.
Russia's latest strikes again hit Ukrainian energy facilities and infrastructure across the country, knocking out power to more than 500,000 people and forcing emergency repairs to the battered grid.
"Once again, there was no early warning from our partners," Zelenskyy said, as he catalogued the damage, deaths and injuries.
A strike near the northeastern city of Kharkiv killed six people, including three children, authorities said.
US Secretary of State Marco Rubio, on a visit to Uzbekistan on Monday, denied that intelligence sharing had been withdrawn with Ukraine and backed Trump's call for Zelenskyy to focus on ending the conflict.