Liz Truss is heading for a furious diplomatic confrontation with France on her first trip abroad as foreign secretary, as anger mounts in Paris over the cancellation of a £48bn nuclear submarine contract. Truss, whose appointment was one of the biggest surprises of Boris Johnson’s cabinet reshuffle last Wednesday, will arrive in the US on Sunday before a four-day visit to New York and Washington during which she is aiming to promote the prime minister’s vision of “global Britain” to international leaders. But on Tuesday, when she convenes a meeting of the permanent five members of the UN security council – the UK, US, France, China and Russia – Truss will come face to face with her French counterpart, Jean-Yves Le Drian, who has described the way France has been treated by the UK, US and Australia over a new tripartite security pact, and the cancellation of the submarine deal, as a “stab in the back” for his country. It is believed that the French president, Emmanuel Macron, had never intended to attend in person but will address the assembly remotely. The French are furious at Australia’s decision to cancel a A$90bn (£48bn) contract it signed with the French company Naval Group in 2016 for a fleet of 12 state-of-the-art attack class submarines. That deal became bogged down in cost overruns, delays and design changes. The new deal will see Canberra acquire nuclear-powered submarines built by the US and the UK, instead of those from France. French newspaper La Tribune described the Australia-UK-US pact, known as Aukus, as a “majestic slap in the face” for all those in France “who still want to believe that Joe Biden will be a different president to Donald Trump in matters of foreign policy”. The French are incensed at not being told by any of the countries involved that the submarine deal was being cancelled and that the new pact was coming into being. Macron learned of the deal in a letter sent by the Australian prime minister, Scott Morrison, to the Élysée shortly before Morrison gave a press conference announcing the Aukus pact. Effectively, Paris was faced with a fait accompli. Diplomatic sources in France say if the Australians were so unhappy with the contract as it stood, it would have been the normal, expected behaviour for them to have expressed their concerns to Paris. Le Drian, the French foreign minister, accused the Americans and Australians of “lies and duplicity” over the Aukus deal. And he warned: “It’s not finished.” He said Australia had told France that it was breaking the submarine contract, and making a new deal with the US and UK, just one hour before Morrison announced this at the press conference. “That is why I say there has been duplicity, contempt and lies, and when you have an ally of the stature of France, you don’t treat them like that,” Le Drian said. Asked if there had been a failure of French intelligence in uncovering the secret deal, he replied: “The agreement project initiated by the US and Australia was decided by a small group and I’m not sure US and Australian ministers knew about it. “When we see the US president with the Australian prime minister announce a new agreement with Boris Johnson, the breach of trust is profound. In a real alliance you talk to each other, you don’t hide things, you respect the other party, and that is why this is a real crisis.” Truss risks finding herself plunged into one of the most bitter and potentially far-reaching diplomatic spats with France in recent memory when she is less than a week into her new role, and as she tries to promote a new, less European-focused foreign policy to the world. Speaking on Saturday night before the trip, Truss sounded upbeat about forging ever-stronger ties with the US in the post-Brexit era. “I’m delighted my first international visit as foreign secretary is to the United States – the UK’s closest and most important partner. At the UN general assembly, I look forward to convening global leaders to tackle the major issues of the day and projecting a positive, outward-looking global Britain that delivers for people across the UK.” Johnson will also travel to the UN meeting and make a speech urging greater progress on climate change before the Cop26 meeting in Glasgow this year. But there are now fears that the argument with the French will overshadow his efforts to bang heads together. Above and beyond the tearing up of the contract, Paris feels the decision of the US and the UK to sideline France, a key Nato ally, gravely damages its relationship with the organisation. While the Élysée has made no public comment on the international row, Macron’s decision to recall its ambassadors from Washington and Canberra is a historic low in diplomatic relations between the countries after what Paris has described as a betrayal and humiliation of a European partner. It is still unclear when the Australians decided that the dozen diesel submarines they had ordered from the French in 2016 would be obsolete before they were ready in the late 2030s or 2040s. But by the time Biden took office, they had made the decision to ask the US for the nuclear propulsion technology Washington had only ever shared with the UK. According to one diplomatic source in Washington, Australian officials first approached the British government to check that London would give its support before going to the Biden administration, knowing they would be pushing at a partially open door. The appointment of Kurt Campbell as Biden’s Indo-Pacific policy coordinator was a sign that the US president was fully behind Campbell’s advocacy of the wholehearted “pivot to Asia”. Officials in Washington played down the impact on the general assembly. “France is not going to pull out of P5 or G7 events,” one said. However, Peter Ricketts, a former permanent undersecretary at the Foreign Office and former UK ambassador to France, said the fallout from the affair would be extensive. “This is much more than a diplomatic spat about an arms deal or recalling ambassadors. The French had invested in a strategic security pact with Australia that they described as structural. Australia has now trashed that,” he said. Lord Ricketts pointed out that France has “territory and military forces” in the Indo-Pacific and that Australia had changed its mind about what kind of submarine it wanted to the detriment of the French. “The [Shortfin] Barracuda is a nuclear submarine by design but Australia said they wanted a conventional submarine. Now Australia says they want nuclear.” He added: “France sees it as a betrayal by the British and the US, who did this secretly with Australia for the last six months. French diplomats have told me that America lied about what they were doing and they will be releasing documents to show that America lied. They are asking themselves, ‘What is the point of being a Nato ally if this is how the US behaves?’” “You will remember about 18 months ago, Emmanuel Macron described Nato as ‘brain dead’ and this will confirm that view. This has caused a huge rift down the middle of Nato.” The former ambassador predicted France would now be looking to allies closer to home to beef up European security and would “pull the shutters down on Nato”.