The US president suspended military aid to Kyiv days after a stunning public clash with Ukrainian President Volodymyr Zelensky in the Oval Office.

"We will do everything to hold out," Prime Minister Denys Shmygal told a press conference in Kyiv.

Washington has been Ukraine's most important military backer since Russia invaded in February 2022, with Shmygal saying US assistance in the form of air defence and intelligence exchanges had saved "thousands, perhaps tens of thousands of Ukrainian lives."

Ukraine said it was in talks with Europe on filling the gap and wanted to negotiate with Trump over the arms halt.

"We are discussing options with our European partners, and of course, we are not overlooking the possibility of negotiations with our American counterparts," Ukrainian presidential adviser Mykhailo Podolyak said on X.

PM Shmygal said, "Ukraine is absolutely determined to continue cooperation with the US."

That includes signing an aborted deal to give the United States preferential access to Ukraine's minerals and natural resources, he said.

Zelensky, who was yet to comment publicly on the halt of aid, went to Washington to sign that deal before it was scrapped after his showdown with Trump and Vice President JD Vance.

Laying out the importance of US support, Shmygal said Tuesday that security guarantees from Washington were of existential importance for both Ukraine and Europe.

"We need and ask for concrete security guarantees, both from the United States of America and from Europe and from the G7 countries. This is existentially important not only for Ukraine, but also for the European Union, for the European continent," he said.