Canadian Prime Minister Mark Carney has called a snap election for April 28, just days after being appointed to the role.
Mr Carney replaced Justin Trudeau just over a week ago as leader of the governing Liberal Party, which is considered centre-left in Canadian politics.
Conservative Party leader Pierre Poilievre had been leading in many published opinion polls in Canada, but escalating tension with the United States has seen the incumbent Liberals regain ground.
The election contest is expected to be dominated by how to handle US President Donald Trump, who has lately been floating the idea of annexing Canada.
Speaking after visiting the Canadian governor-general and calling the election, Mr Carney repeatedly labelled tariffs against Canada as "unjustified" and vowed to take up the fight to Mr Trump.
"[Mr Trump] wants to break us so America can own us. We will not let this happen," he said.
"We are facing the most significant crisis of our lifetimes because of President Trump's unjustified trade actions and his threats to our sovereignty."
Mr Carney also announced tax cuts for the middle class and deepening trade and defence ties with partners, including with the UK and France.
"This week we reached a new agreement on national defence with Australia to protect Canada," he said, referring to the $6.5 billion purchase of new radar equipment.
Mr Trump has repeatedly labelled Canada the 51st state and called Mr Carney's predecessor "Governor Trudeau".
He also placed tariffs on Canadian goods and doubled the rate of his global tariffs on steel and aluminium specifically for Canada.
Conservatives distance themselves from Trump
Mr Carney has accused Mr Poilievre of being allied with Mr Trump, a claim the opposition leader denied as he launched the Conservatives' election campaign.
"I will insist the president recognises the independence and sovereignty of Canada. I will insist he stops tariffing our nation," Mr Poilievre said.
"I know a lot of people are worried, angry and anxious. And with good reason as a result of the president's unacceptable threats against our country."
The Conservatives had hoped to make the election about Mr Trudeau, whose popularity declined as food and housing prices rose and immigration surged.
But after decades of bilateral stability, the vote is now expected to focus on who is best equipped to deal with Mr Trump.
The US president's aggressive statements have prompted a wave of anger, with many Canadians boycotting American products and one provincial premier threatening to suspend electricity exports to three US states.
New to politics, Carney calls for mandate
Mr Carney is a former central banker in Canada and the UK with no previous political or election campaign experience.
He won the Liberal leadership two weeks ago by persuading party members he was the best person to tackle Mr Trump.
Laura Stephenson, a politics professor at Western University in the Canadian city of London, said Mr Carney's inexperience might not be that important given the Trump factor.
"There's a different kind of comparison that's being made right between the leaders and what are they going to be able to do," she said.
"I have a feeling we're going to see a little more grace extended than is usually given to politicians during this campaign."
Upon being appointed prime minister on March 14, Mr Carney had indicated he would seek a mandate from voters and head to an early election.
He had until October to call an election.
ABC/wires
