US President Donald Trump says he will send Patriot air defence missiles to Ukraine, calling them necessary to defend the country.
The announcement comes amid a diplomatic flurry set for Monday, with the US special envoy starting his latest trip to Ukraine and Mr Trump set to meet with NATO Secretary-General Mark Rutte in Washington.
Mr Trump did not reveal the number of Patriots he planned to send to Ukraine, but said the US would be reimbursed for their cost by the European Union.
"We will send them Patriots, which they desperately need, because [Russian President Vladimir] Putin really surprised a lot of people," Mr Trump said.
"He talks nice, and then bombs everybody in the evening."
Mr Trump has grown increasingly disenchanted with Mr Putin because the Russian leader has resisted the US president's attempts to negotiate a ceasefire between his country and Ukraine.
Ukrainian President Volodymyr Zelenskyy has asked for more defensive capabilities to fend off a daily barrage of missile and drone attacks from Russia.
Moscow's offensive on Ukraine has lasted for more than three years, with attacks intensifying this northern summer and US-led negotiations so far yielding no success in ending the fighting.
The White House has done a U-turn from an announcement earlier this month that it would pause some arms deliveries to Kyiv, instead announcing a new deal which would involve NATO paying the US for some of the weapons it sends to Ukraine.
"We basically are going to send them various pieces of very sophisticated military equipment," Mr Trump said. "They are going to pay us 100 per cent for that, and that's the way we want it.
"It'll be business for us."
Mr Trump plans to meet Mr Rutte to discuss Ukraine and other issues this week.
New Patriot systems agreement
Last week, Mr Zelenskyy said Ukraine was "close to reaching a multi-level agreement on new Patriot systems and missiles for them".
Mr Trump has repeatedly voiced displeasure with Mr Putin in recent days. On Sunday, he hinted he might finally be ready to toughen sanctions as momentum grows for a deterrent package in the US Congress.
When he first returned to the White House in January, Mr Trump insisted he could work with the Russian leader to end the war, holding off on hiking sanctions, unlike European allies.
But Russia has, for months, refused a ceasefire proposed by the US and Kyiv.
When asked about whether he would announce any sanctions against Russia, Mr Trump responded: "We're going to see what we will see tomorrow, OK?", before repeating plans to meet with Mr Rutte.
'Sledgehammer' sanctions
Earlier on Sunday, US senators touted a bipartisan bill that would arm Mr Trump with "sledgehammer" sanctions to use against Russia.
The sanctions bill would allow the president "to go after Putin's economy, and all those countries who prop up the Putin war machine," Republican senator Lindsey Graham told CBS News.
"It would give President Trump the ability to impose 500 per cent tariffs on any country that helps Russia," Senator Graham said, adding that those could include economies that purchase Russian goods like China, India or Brazil.
"This is truly a sledgehammer available to President Trump to end this war," he said.
"Without a doubt, this is exactly the kind of leverage that can bring peace closer and make sure diplomacy is not empty," Mr Zelenskyy said about the proposed bill in a post on X.
Senator Graham and Democratic senator Richard Blumenthal were also due to meet Mr Rutte on Monday night.
Snator Blumenthal told CBS News they would also discuss the legally thorny issue of unlocking frozen Russian assets in Europe and the US for access by Ukraine.
"The $US5 billion ($7.62 billion) that the United States has also could be accessed, and I think it's time to do it," said Senator Blumenthal.
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