By Promit Mukherjee and David Ljunggren OTTAWA (Reuters) -Ex-central banker Mark Carney was formally sworn in as prime minister of Canada on Friday, putting him in a position to fight tariffs from U.S.

Mark Carney, an economist with decades of experience in banking who is new to politics, is slated to become Canada's next leader. He says he'll fight against President Trump's threats of tariffs and making Canada the "51st state.

Carney, 59, replaces Prime Minister Justin Trudeau, who announced his resignation in January but remained in power until the Liberal Party elected a new leader. Carney is widely expected to trigger a general election in the coming days or weeks.

Top diplomats from the Group of 7 industrialized democracies agreed Friday on a joint statement expressing support for Ukraine and a U.S. ceasefire proposal in the three-year-old war even as President Donald Trump’s trade policies and taunts toward host Canada overshadowed the talks.

Diplomats from the G7 nations were set to negotiate late into the night over a joint statement to show a united front in Canada on Thursday after weeks of tension between U.S. allies and President Donald Trump over his upending of Western trade and security policy.

U.S. Secretary of State Marco Rubio will likely hear a litany of complaints as he meets with the foreign ministers of Britain, Canada, France, Germany, Italy and Japan.

On Thursday, the president said the halted Constitution Pipeline could save Northeast families thousands on their utility bills.

President Donald Trump backed down from an extraordinary trade war escalation Tuesday that had threatened a massive surge in Canadian steel and aluminum tariffs and new tariffs on Canadian electricity.

President Donald Trump openly challenged U.S. allies on Wednesday by increasing tariffs on all steel and aluminum imports to 25% as he vowed to take back wealth “stolen” by other countries, drawing quick retaliation from Europe and Canada.