Ukraine said on Tuesday it would do all it can to maintain its ties with the United States, after President Donald Trump paused military aid to Kyiv in the most dramatic step yet in his pivot towards closer ties with Russia.

Trump has upended US policy on Ukraine and Russia, culminating in an explosive confrontation at the White House on Friday, when Trump upbraided President Volodymyr Zelenskiy for being insufficiently grateful for Washington’s backing.

“President Trump has been clear that he is focused on peace. We need our partners to be committed to that goal as well. We are pausing and reviewing our aid to ensure that it is contributing to a solution,” a US official said on Monday.

Ukraine’s Prime Minister Denys Shmyhal said Kyiv still had the means to supply its frontline forces. US military aid was precious and saving thousands of lives, he said, and Kyiv would do all it could to maintain relations with Washington.

“We will continue to work with the US through all available channels in a calm manner,” Shmyhal told a press conference. “We only have one plan - to win and to survive. Either we win, or the plan B will be written by someone else.”

The Kremlin, for its part, said cutting off military aid to Ukraine was the best possible step towards peace, although it was still waiting to confirm Trump’s move.

Military experts say it could take time for the impact of missing US aid to be felt on the battlefield. When US assistance was held up for several months last year by Republicans in Congress, the most notable initial impact was shortages of air defences to shoot down incoming Russian missiles and drones. Later, Ukrainian forces in the east complained of shortages of ammunition, including for artillery.

The pause puts more pressure on European allies, led by Britain and France, whose leaders both visited the White House last week and have publicly embraced Zelenskiy since the Oval Office blow-up.

Europeans are racing to boost their own military spending and provide alternative support for Kyiv, including a plan to put troops on the ground to support any ceasefire, though they say they still need some form of US support.

France condemned the aid freeze. Suspending arms to Ukraine made peace “more distant, because it only strengthens the hand of the aggressor on the ground, which is Russia,” said French junior minister for Europe, Benjamin Haddad.

Britain was more circumspect. A government spokesperson said London remained committed to securing peace in Ukraine.

Ukrainians, who have endured three years of war against a more powerful foe, were stunned by a move many described as a betrayal. Oleksandr Merezhko, head of the Ukrainian parliament’s foreign affairs committee, said it looked like Trump was “pushing us towards capitulation”.

“Yes, it is betrayal, let’s call it like it is,” said lawyer Olena Bilova, 47 in Kyiv. “But let’s hope that American civil society and the elites of the European Union will not leave us alone.”

European Commission President Ursula von der Leyen unveiled proposals to boost spending on defence in the EU, which she said could mobilise up to 800 billion euros ($840 billion). The EU is holding an emergency summit on Thursday.

‘KICKED THE DOOR WIDE OPEN FOR PUTIN’

Since Russia’s invasion three years ago, the US Congress has approved $175 billion in total assistance for Ukraine, according to the nonpartisan Committee for a Responsible Federal Budget.

The Trump administration inherited $3.85 billion worth of Congressionally approved authority to dip into US arms stocks for Ukraine. Monday’s move also appeared to halt deliveries of military equipment approved by former President Joe Biden, including munitions, missiles and other systems.

Trump’s abrupt pivot towards Russia may be the most dramatic US geopolitical shift in generations. Defending Europe from a hostile Kremlin has been the lodestar of US foreign policy under both parties since the 1940s. Trump’s moves have appalled Democrats and some Republicans, although there has been little pushback from Republican leaders in Congress, including those who were once strong backers of Ukraine.

“By freezing military aid to Ukraine, President Trump has kicked the door wide open for Putin to escalate his violent aggression against innocent Ukrainians,” said Senator Jeanne Shaheen, the top Democrat on the Senate Foreign Relations Committee.

Trump suggested on Monday that a deal to open up Ukraine’s minerals to US investment could still be agreed, and Shmyhal said Ukraine could still sign it. The deal was meant to be signed in Washington on Friday before Zelenskiy departed after the Oval Office bust-up.

When asked on Monday if the deal was dead, Trump said: “No, I don’t think so.”

In an interview on Fox News, Vice President JD Vance called on Zelenskiy to accept it.

“If you want real security guarantees, if you want to actually ensure that Vladimir Putin does not invade Ukraine again, the very best security guarantee is to give Americans economic upside in the future of Ukraine,” Vance said.

Zelenskiy has made clear that a ceasefire must carry explicit security guarantees from the West to ensure that Russia, which holds about 20% of Ukraine’s land, does not attack again. Trump has so far refused to give any such guarantees.