Joe Biden will make his first speech to the United Nations as president on Tuesday, seeking to “close the chapter on 20 years of war” and begin an era of intensive diplomacy. Biden will however have to contend with hostility from China, an open rift with France and widespread scepticism among UN member states over his commitment to multilateralism following disagreements over Israel, a chaotic withdrawal from Afghanistan, and a nuclear submarine deal that took adversaries and allies by surprise. The White House sees the speech to the UN general assembly as a chance to reclaim the global initiative and convince UN member states that “America is back”, as Biden promised when he took office. It will be followed by a week of bilateral meetings, a US-hosted Covid summit on Wednesday aimed at drumming up more funding for global vaccine distribution, a meeting of leaders of the Pacific-oriented Quad group– India, Australia and Japan – on Wednesday, and a UN security council meeting on climate insecurity on Thursday. “It’s an important, consequential week for President Biden and his leadership on the world stage,” a senior administration official said. Tuesday’s speech, the official added, will “center on the proposition that we are closing the chapter on 20 years of war, and opening a chapter of intensive diplomacy, by rallying allies and partners and institutions to deal with the major challenges of our time.” However, Biden is arriving in New York just days after the disclosure of a new security agreement between Australia, the UK and US, which will involve helping Australia build a fleet of nuclear-powered submarines. The announcement of the Aukus deal has deepened tensions with China, which portrayed it as a hostile act, and with France, which had a contract to supply Australia with French vessels and which was blindsided by Aukus. In his speech, Biden will say he wants to avoid a new cold war with the world divided into blocks. “He believes in vigorous, intensive, principled competition that does not tip over into conflict,” a senior US official said. However, at the start of UN general assembly’s summit week, the UN secretary general, António Guterres, expressed concern that US-Chinese rivalry was stopping progress on urgent global issues. Guterres told CNN that the efforts of US climate envoy John Kerry to reach a compromise with China have “largely failed because the Chinese have said … we cannot have cooperation on climate or anything else”. “I believe that we need to avoid a new cold war, because the old cold war was more easy to manage. It was clear. Now things are more complex,” the secretary general said. Biden starts the week with the added burden of a serious fracture in western cohesion. France is still furious at being taken by surprise by the Aukus agreement and warning there will be further diplomatic fallout. On Monday, Biden was trying to set up a phone call with French president Emmanuel Macron, and US secretary of state, Tony Blinken, was seeking a meeting with his counterpart, Jean-Yves Le Drian, in New York, but the French were being elusive. The state department said the schedules of Blinken and Le Drian were “dynamic”, but a few hours later the French foreign minister made clear he had no plans to meet before a call was arranged between Biden and Macron. “I myself do not intend to meet Secretary of State Blinken, “though I might see him here or there, in a corridor”, Le Drian said. He said that the Aukus row was not just about the submarine contract, and the breach of trust involved in keeping the deal secret, but also about the future of multilateralism and strategy in the Indo-Pacific. “We consider that this [US] approach is very about confrontation with China,” he told reporters in New York, arguing that Europe’s approach would be more nuanced and should be taken into account. Richard Gowan, the UN director for the International Crisis Group, said that the Aukus row “will fit in with a narrative that has emerged around Biden that he talks a good multilateral game, but when it comes to the crunch on a lot of issues he is still a bit of an America First-er.” In May, the US blocked the UN security council from making a statement calling for an end to Israeli-Palestinian violence, while Israel was conducting a bombing campaign aimed at Hamas in Gaza, with heavy civilian casualties. Sherine Tadros, the head of the New York office of Amnesty International, said that Biden will benefit from the comparison with Donald Trump, who was openly hostile to the UN, and delivered bellicose speeches from the lectern. “The bar is low,” Tadros said. “There is no doubt there is reengagement … But when you look at Afghanistan, when you look at the Gaza war, the UN was circumvented by the Biden administration and treated as a Plan B.” In normal times, Biden would have found it easier to smooth over cracks by schmoozing with fellow leaders, but Covid-19 and New York City rules for preventing its spread have made that difficult. He is due to hold only one bilateral meeting in New York on Tuesday, with Australian prime minister Scott Morrison, before returning to Washington, where he will meet Britain’s Boris Johnson.