EU chief Charles Michel on Friday told Donald Trump to "get the facts straight" on support for Ukraine, after the US presidential challenger said Europe should be giving Kyiv more money.

"Don't be intimidated by (Russian President Vladimir) Putin. We aren't," the European Council president wrote in a post addressed to Trump on X.

"Let's get the facts straight. The numbers speak for themselves. EU contribution to Ukraine: EUR143 billion ($150 billion)."

Former US leader Trump on Thursday told Europe to "get moving" on support for Ukraine ahead of a vote this weekend by US lawmakers on a long-delayed $61 billion aid package for the war-torn nation.

"As everyone agrees, Ukrainian Survival and Strength should be much more important to Europe than to us, but it is also important to us! GET MOVING EUROPE!" Trump wrote on his social media platform Truth Social on Thursday.

Despite not holding office, the former US president exercises tight control over many Republicans in Washington, who have delayed granting new military aid funds to Ukraine. They insist on prioritising the fight against illegal immigration at the Mexican border.

The deadlock between Democrats and Republicans has left Ukraine short of ammunition and defense systems and caused it to suffer setbacks in the war that began with the Russian invasion in February 2022.

Trump, who will battle President Joe Biden for the White House in November, wrote: "Why is it that the United States is over $100 Billion Dollars into the Ukraine War more than Europe, and we have an Ocean between us as separation!

"Why can't Europe equalise or match the money put in by the United States of America in order to help a Country in desperate need?"

The Germany-based Kiel Institute, which has been tracking aid to Ukraine, said that as of the beginning of this year, the EU and its member states were the biggest donors with 144.1 billion euros in pledges, followed by the United States with 67.7 billion euros.

However the EU had only allocated 77.2 billion euros as much of the pledges were for several years.

The US House of Representatives is set to vote Saturday on a new military aid package that would unlock billions of dollars for Ukraine, Israel and Taiwan.

Biden has called for Congress to pass the package, vowing that he would sign the law immediately.

During the months the US package has been stalled in Congress, EU nations have signed off on military and budgetary support worth tens of billions of dollars for Ukraine.

But Europe has struggled to keep Ukraine armed while military superpower the United States has been mired in political wrangling, leaving Kyiv's forces on the front line outgunned.

During his time in office and since, Trump has repeatedly attacked Washington's European allies for not spending enough on their own defences.

He has rocked the NATO alliance by suggesting he wouldn't protect countries not spending enough on defence. NATO countries have committed to spend at least 2 percent of their GDP's on defence, with 20 out of 32 members expected to hit that bar this year.