New Foreign Secretary Liz Truss has launched a strong defence of the UK’s security pact with the US and Australia amid a deepening diplomatic row with France.

Ms Truss said the agreement – which will see the UK and US co-operate to develop a new fleet of nuclear-powered submarines for the Australian navy – showed Britain’s readiness to be “hard-headed” in defence of its interests.

The deal has infuriated Paris after 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.

Writing in The Sunday Telegraph, Ms Truss, who was the big winner in Boris Johnson’s Cabinet reshuffle, made no mention of the the diplomatic stand-off with the French.

Earlier, however, a French minister scornfully referred to the UK as the “junior partner” in the trilateral agreement – known as Aukus- and accused it of returning to hide in the “American lap”.

In her article, Ms Truss said the agreement, widely seen as a counter to increasing Chinese military assertiveness in the region, underlined the UK’s commitment to the Indo-Pacific.

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

“But freedoms need to be defended, so we are also building strong security ties around the world,” she wrote.

“That is why last week the Prime Minister announced, alongside our friends President Biden and Prime Minister Morrison, the creation of a new security partnership called Aukus.

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

President Emmanuel Macron reacted to the pact by ordering the recall of the French ambassadors to Washington and Canberra – a move virtually unprecedented among such close allies.

There was, was however, no similar order to return to Paris for the French envoy to London.

But in a series of acid-tongued interviews with French television, Europe Minister Clement Beaune suggested it was because the UK was the “junior partner” which had accepted its “vassalisation” by the US.

“Our British friends explained to us they were leaving the EU to create Global Britain. We can see that this is a return into the American lap and a form of accepted vassalisation,” he said.

“The UK is clearly trying to find its feet, perhaps there was a lack of thought about the strategic future. Today they are hiding in the American fold. I hope that will not be their policy for the decades to come.”

He later added: “We see through this partnership, this strategic alliance and after the Kabul crisis, that Global Britain seems to be more about a US junior partner than working with different allies.”

In the Commons on Thursday, Boris Johnson sought to smooth over the differences, insisting relations with France remained “rock solid” while Downing Street described Paris as “a close ally and friend” of the UK.

Nevertheless, the Prime Minister also made clear he expected the agreement to bring “hundreds” of highly-skilled jobs to Britain – jobs which may well have otherwise gone to France.

The French were reportedly furious they had not only lost the contract, but were given just a few hours’ notice of the new agreement ahead of what are expected to be a tough election year for Mr Macron.

French foreign minister Jean-Yves Le Drian said it was a “stab in the back” and constituted “unacceptable behaviour between allies and partners”.

The pact between the UK, US and Australia has been widely seen as an attempt to counter the growing military assertiveness of China in the Indo-Pacific region.

Beijing swiftly denounced the initiative as “extremely irresponsible” and a threat to regional peace and stability.

Mr Johnson, however, said it was not intended as an “adversarial” move against China or any other power.