France, UK To Support Ukraine 'For As Long As It Takes': Cameron

France and the UK will support Ukraine in its fight against the Russian invasion "for as long as it takes", British Foreign Secretary David Cameron said Tuesday, adding it was "essential" that President Vladimir Putin was defeated.

His comments came as concern grows in Kyiv that Western patience and unity could be cracking in the fight against Russia, almost two years after the invasion began in February 2022.

"Britain and France have been staunch supporters of Ukraine and we will continue to be for as long as it takes," Cameron said after talks in Paris with French counterpart Catherine Colonna, adding: "I have no doubt that we can make sure Putin loses and it is essential he does lose."

"We must be absolutely staunch in how we back Ukraine," he said.

The White House warned Monday that the United States has only enough authorised funding for one more aid package to Ukraine this year, with hardline Republicans in Congress blocking additional aid.

Insisting that the West must stay the course, Cameron compared the fight against the Russian invasion to a play in different acts.

"The first act was the stunning failure of Russia to achieve its objectives" in the initial phase of the invasion, said Cameron.

"The second act was the brilliance the Ukrainians showed in driving back the Russians... and of course the third act has been more difficult on land," he said in apparent reference to the failure of the Ukrainian counteroffensive this summer to achieve a breakthrough.

Cameron, the former prime minister who was unexpectedly appointed Britain's top diplomat last month, added: "But the fourth act is yet to be written and we must be sure we write it in the correct way."

Both Cameron and Colonna were eager to emphasise that Britain and France were on the same page over the major international issues, including Ukraine and the Middle East, even after Brexit.

"Our two countries, shoulder-to-shoulder since the beginning, have worked together to ensure that Russian aggression cannot be rewarded, that it is a failure and that Ukraine can recover its freedom, its sovereignty, its territorial integrity," said Colonna.

"We hope that this cooperation can be further strengthened," she added.