Boris Johnson urged French president Emmanuel Macron not to “worry” about the military alliance Britain formed with the US and Australia, despite it having sparked an extraordinary diplomatic row with France.

The Prime Minister insisted Anglo-French relations were “ineradicable” on Sunday after France suggested the UK was a lapdog to Joe Biden’s White House during a verbal attack.

Dubbed Aukus, the agreement brokered last week will see the UK and US co-operate to develop a new fleet of nuclear-powered submarines for the Australian navy.

But the deal enraged Paris when the Australians announced they were pulling out of a £30 billion agreement with the French to supply it with less-capable conventionally-powered diesel-electric vessels.

In a virtually unprecedented step among allies, Mr Macron ordered the recall of the French ambassadors to Washington and Canberra.

No such step followed for London, and France’s Europe Minister Clement Beaune suggested it was because the UK was the “junior partner” which had accepted its “vassalisation” by the US.

But Mr Johnson insisted Britain and France have a “very friendly relationship”, which he described as being of “huge importance”.

“Our love of France is ineradicable,” he told reporters travelling with him on the RAF Voyager to New York, where he will take part in the United Nations General Assembly.

“Aukus is not in any way meant to be zero-sum, it’s not meant to be exclusionary. It’s not something that anybody needs to worry about and particularly not our French friends.”

New Foreign Secretary Liz Truss touched down in New York alongside Mr Johnson as they both prepare to meet US President Joe Biden in Washington on Tuesday.

She launched a defence of the agreement, widely seen as a counter to increasing Chinese military assertiveness in the region, in an article for the Sunday Telegraph.

Ms Truss said Britain would always be a “fierce champion” of freedom and free enterprise around the world.

“It shows our readiness to be hard-headed in defending our interests and challenging unfair practices and malign acts,” she added

She will also attend the UN summit, where she will come into contact with the French, though the extent of any conversations was unclear.

French foreign minister Jean-Yves Le Drian described the deal as a “stab in the back” and constituted “unacceptable behaviour between allies and partners”.

In an interview with France 2 television, Mr Le Drian accused Australia and the US of “duplicity, disdain and lies” and said the recalling of France’s ambassadors “signifies the force of the crisis today”.

He said allies “don’t treat each other with such brutality, such unpredictability, a major partner like France … So there really is a crisis”.