Lord Cameron urges US Congress to back Ukraine funding package
Lord Cameron has urged the United States Congress to back a fresh package of military support for Ukraine.
Writing for US political news website, The Hill, the UK foreign secretary warned against showing "the weakness displayed against Hitler in the 1930s".
A bill promising Ukraine almost $60bn (£50bn) in military aid passed the Senate on Tuesday.
But Republican leaders are threatening to block it in the House of Representatives.
Lord Cameron's comments amount to a robust intervention in domestic US politics by the foreign minister of an ally.
Urging Congress to support the funding package, he said he was "going to drop all diplomatic niceties".
"I believe our joint history shows the folly of giving in to tyrants in Europe who believe in redrawing boundaries by force," he wrote.
"I do not want us to show the weakness displayed against Hitler in the 1930s. He came back for more, costing us far more lives to stop his aggression.
'Watching'
"I do not want us to show the weakness displayed against Putin in 2008, when he invaded Georgia, or the uncertainty of the response in 2014, when he took Crimea and much of the Donbas - before coming back to cost us far more with his aggression in 2022."
During a visit to Poland, the foreign secretary said he was "not wanting in any way to lecture American friends, or tell American friends what to do".
But he added: "We must not let Putin think he can out-wait us or last us out, and that's why this vote in Congress is so crucial."
He also warned that other countries around the world would be watching. "They will be watching in China, they will be watching in Iran," the former prime minister told reporters.
Lord Cameron's intervention has prompted criticism from some Republicans.
House of Representatives Republican and Trump supporter Marjorie Taylor Greene told Sky News: "David Cameron needs to worry about his own country and, frankly, he can kiss my ass."
And Matt Rosendale, another member of the House, told BBC Radio 4's The World Tonight: "He should focus on his own government and not on the US government."
"The impact right now from someone else trying to make recommendations to the US House of Representatives is going to be minimal at best," he said, adding: "I answer to the people of Montana, not to England."
Lord Cameron has been visiting Bulgaria and Poland ahead of the Munich Security Conference, where he is expected to urge his counterparts to boost defence production for Ukraine.
The Senate approved the aid package, which included funding for Ukraine, Taiwan, Israel's war against Hamas, and for humanitarian aid in conflict zones including Gaza, after months of political wrangling.
It passed the Democratic-controlled Senate by 70 to 29, despite a small group of Republicans voting against. However, it faces an uphill battle in the House.
The bipartisan support came despite former President Donald Trump's criticism of the bill for its lack of funding to secure the US-Mexico border.
Conservative Republicans have objected to sending billions overseas without first tackling the migrant crisis on the southern US frontier and had demanded any foreign aid be tied to more security measures at the border.
Republican House Speaker Mike Johnson suggested in a statement on Monday night the new bill would not pass the Republican-controlled lower chamber of Congress without such provisions.