US President Donald Trump injected fresh drama into an already tense meeting of the Group of Seven major industrialised nations on Friday by calling for Russia, ousted for its the annexation of Crimea, to be reinstated. Mr Trump made the comment at the White House after hours of further escalating his rhetoric against longtime allies over US trade practices. "Why are we having a meeting without Russia in the meeting? he said. "They should let Russia come back in because we should have Russia at the negotiating table." Solidifying his solo status on the world stage, Mr Trump also lashed out at longtime allies over their criticism of his trade policies and plans an early exit from the G7 meeting. Russia was ousted from the elite group in 2014 as punishment for President Vladimir Putin's annexation of Crimea and its support for pro-Russian separatists in Ukraine. In the US, special counsel Robert Mueller is investigating whether Mr Trump's campaign colluded with Russia in a bid to sway the 2016 presidential election in his favour. Mr Trump will arrive on Friday at the annual gathering, held this year at a Quebec resort, but will leave on Saturday morning before the event is over, heading to Singapore for his highly anticipated summit with North Korean leader Kim Jong-un. The White House announced his travel plans after French President Emmanuel Macron and Canadian Prime Minister Justin Trudeau signalled they would use the G7 event to take a stance against new US tariffs on steel and aluminium imports. "Looking forward to straightening out unfair Trade Deals with the G-7 countries," Mr Trump tweeted early on Friday. "If it doesn't happen, we come out even better." He also singled out tariffs on US dairy products in yet another scathing tweet directed at Canada just before the G7. At a joint press conference on Thursday, Mr Macron said: "A trade war doesn't spare anyone. It will start first of all to hurt US workers." Mr Trudeau said: "We are going to defend our industries and our workers." The Canadian prime minister said Mr Trump's action would hurt American workers as well as Canadians. "If I can get the president to actually realise that what he's doing is counterproductive for his own goals as well, perhaps we can move forward in a smarter way," he said. As tempers frayed, Mr Trump had a ready retort, via tweet: "Please tell Prime Minister Trudeau and President Macron that they are charging the US massive tariffs and create non-monetary barriers. The EU trade surplus with the US is $151 Billion, and Canada keeps our farmers and others out. Look forward to seeing them tomorrow." Later on Thursday, he tweeted: "Prime Minister Trudeau is being so indignant, bringing up the relationship that the US and Canada had over the many years and all sorts of other things...but he doesn't bring up the fact that they charge us up to 300% on dairy — hurting our Farmers, killing our Agriculture!" A few hours later, he added: "Take down your tariffs & barriers or we will more than match you!" With a cool reception all but assured, Mr Trump has complained to aides about even having to attend the meeting, especially since his summit with Mr Kim is just days away. Late on Thursday, the White House announced that Mr Trump would be leaving the G7 on Saturday morning to head to Singapore for his summit with Kim, even though the G7 meeting is scheduled to continue until later that day. Mr Trump will miss the G7 meetings on climate change, clean energy and ocean protection. This marks Mr Trump's second summit of the G7, an informal gathering that meets every year under a rotating chairmanship. The member countries are Canada, France, Italy, Japan, Germany, the United States and Britain. The European Union also attends. Mr Trump is set to hold a series of group and one-on-one meetings, including with Mr Trudeau and Mr Macron. Under Mr Trump, the US has abandoned its traditional role in the G7. His predecessors pressed for freer global trade and championed a trading system that required countries to follow World Trade Organisation rules. Mr Trump's policies have been more protectionist and confrontational, driven by a perception that the US has been the victim of poorly conceived trade deals. Relations have hit such a low that a key question now is whether the seven countries can agree on a joint statement of priorities at the conclusion of the meeting. A gathering of G7 finance ministers days earlier concluded last week with a message of <a href="https://www.thenational.ae/world/the-americas/us-isolated-as-g7-ministerial-meeting-closes-1.736316">"concern and disappointment"</a> for Mr Trump from the other six countries. France's finance minister described the group as "far more a G6 plus one than a G7". Mr Macron made clear on Thursday that the other six countries would not hesitate to go it alone. On Twitter, he said: "The American President may not mind being isolated, but neither do we mind signing a 6 country agreement if need be." Mr Trump's top economic adviser, Larry Kudlow, has been vague on the outcome of the summit, saying on Wednesday: "For these kind of decisions, let them meet first. Let them meet; let them discuss. And then we'll see what happens." Tension has been building over a year of policymaking that has distanced the US from traditional allies, including by Mr Trump's decisions to withdraw the US from the Paris climate accord and the Iran nuclear agreement. The new tariffs — 25 per cent on imported steel, 10 per cent on aluminium from Canada, Mexico and the European Union — threaten to drive up prices for American consumers and companies and heighten uncertainty for businesses and investors around the globe. Canada and other US allies are retaliating with tariffs on US exports. Canada is waiting until the end of the month to apply them with the hope the Trump administration will reconsider. Meanwhile, talks to renegotiate the North American Free Trade Agreement that eliminated most tariffs and duties between the US, Canada and Mexico appear to have ground to a halt. Mr Trump injected further uncertainty recently when he floated the idea of replacing Nafta with two separate trade deals, one with each country. Critics argue that the growing US isolation is risky at a time when Mr Trump is making diplomatic overtures with North Korea and in the Middle East and could use the support of allies. Sebastian Mallaby, a senior fellow with the Council on Foreign Relations, described the relationships between the US and the rest of the G7 as at a "new level of crisis", saying that it was not just about trade but "a general US attitude toward the system". Despite the conflict, Mr Mallaby predicted that the countries would still seek to work with the US, calling it "the indispensable country". Likewise, Mr Macron described the moment as a period of "great challenges", but also defended his efforts to befriend the American president, saying the US was a historical ally and "we need them"