Justin Trudeau's tenure as prime minister began on November 4, 2015, when the first Cabinet headed by him was sworn in by Governor General David Johnston. Trudeau was invited to form the 29th Canadian Ministry and become Prime Minister of Canada following the 2015 election, where Trudeau's Liberal Party won a majority of the seats in the Canadian House of Commons, leading to the resignation of Conservative Prime Minister Stephen Harper.
Since the day of him assuming the office, Trudeau has attempted to distance his governing style from that of his predecessor. One of his first acts was proclaiming that "government by cabinet is back", a signal of an attempt to decentralize power from the Prime Minister's Office and give Cabinet a larger role in governing.
In July 2016, Trudeau announced the formation of the first Prime Minister's Youth Council. Thirty Canadians aged 16 to 24 will comprise the board, which will advise the prime minister on education, economy, climate change and other issues affecting youth.
Trudeau has been urged to stop the $15-billion arms deal with Saudi Arabia – believed to be the largest arms sale in Canadian history. The Saudi Arabian-led intervention in Yemen has been criticized for "indiscriminately targeting civilians". Saudi Arabia is also accused of massive human rights violations. Trudeau has defended the Harper-negotiated arms deal with Saudi Arabia as "a matter of principle." He said: "It’s important that people know that when they sign a deal with Canada, a change of government isn’t going to lead to the contract being ripped up."