US President Donald Trump said Sunday that the United States will send Patriot air defense systems to Ukraine to help it fight Russia's invasion.

Speaking to reporters at Joint Base Andrews outside Washington, DC, Trump did not specify how many systems would be sent to Ukraine.

"We will send them Patriots, which they desperately need, because Putin really surprised a lot of people. He talks nice and then bombs everybody in the evening. But there's a little bit of a problem there. I don't like it," Trump said.

The announcement comes as Trump has grown increasingly frustrated with Russian President Vladimir Putin and the lack of progress on securing peace in Ukraine.

It also comes less than two weeks after the Pentagon said it was pausing some arms shipments to Kyiv, with the White House pointing to dwindling US stockpiles.

During the US election campaign before he returned to the White House in January, Trump had promised to end the war in Ukraine. 

But his attempts to convince Putin to end the war or agree to a ceasefire have so far failed.

Trump says EU will reimburse US for Patriot costs 

Trump is due to meet with NATO Secretary General Mark Rutte to discuss Ukraine and other issues on Monday. Last week, the US leader hinted during an interview with NBC News that he would make "a major statement" on Russia on Monday, without providing further details.

The delivery of Patriot missiles would be paid for by NATO and the European Union, Trump said.

"We basically are going to send them various pieces of very sophisticated military equipment. They are going to pay us 100% for them, and that's the way we want it," Trump said.

"We are not paying anything for it, but we will send it. It will be business for us," he added.

At an international conference in Rome last week focusing on Ukraine's recovery, German Chancellor Friedrich Merz said his country was prepared to purchase Patriot missile systems for Kyiv.

The Patriot is one of the world's most advanced air-defense systems and is capable of intercepting aircraft as well as ballistic and cruise missiles.

Edited by: Louis Oelofse