The United States will continue its “close co-operation” with the UK in the wake of Boris Johnson’s resignation, President Joe Biden has said.

In a brief statement which did not mention the Prime Minister by name or refer directly to his departure, Mr Biden said his administration would continue to work with the UK Government alongside other allies and partners.

“The United Kingdom and the United States are the closest of friends and allies, and the special relationship between our people remains strong and enduring,” the president said in the statement reported by the ABC network.

“I look forward to continuing our close co-operation with the Government of the United Kingdom, as well as our allies and partners around the world, on a range of important priorities.

“That includes maintaining a strong and united approach to supporting the people of Ukraine as they defend themselves against Putin’s brutal war on their democracy, and holding Russia accountable for its actions.”

While both leaders have strongly supported Ukraine, there have been differences on other issues including Brexit – with concerns in the White House that Mr Johnson’s efforts to overturn the Northern Ireland Protocol could jeopardise the peace process.

Elsewhere the EU’s former chief Brexit negotiator Michel Barnier welcomed Mr Johnson’s departure as an opportunity to reset relations between London and Brussels.

“The departure of Boris Johnson opens a new page in relations with the UK,” he tweeted.

“May it be more constructive, more respectful of commitments made, in particular regarding peace and stability in Northern Ireland, and more friendly with partners in the EU.”