US President Joe Biden has spoken to Canadian Prime Minister Justin Trudeau in his first bilateral meeting with a foreign leader since taking office.
The two leaders highlighted mutual policy priorities around climate change and China.
They vowed to align climate goals to achieve net zero emissions by 2050.
And Mr Biden said the US would help Canada secure the release of two Canadians held by Beijing, saying they were not bartering chips.
Canada is often the destination chosen for a US president's first foreign trip, but Covid-19 scuppered Mr Biden's plans. Instead, the meeting was held remotely.
Mr Biden, a Democrat, is hoping to hit the reset button with Mr Trudeau, a Liberal, whose relationship with the former Republican US President Trump was often considered rocky.
Mr Trudeau also pledged to work with the US to "get through Covid but also to make sure we're pulling our weight around the world".
The leaders did not take questions from journalists, which is unusual in Washington for a bilateral event such as this.
What was said on climate change?
Mr Trudeau in his opening remarks criticised the Trump administration, and thanked Mr Biden for "stepping up".
The prime minister added: "As we are preparing the joint rollout and communique... it's nice when the Americans aren't pulling out all references to climate change."
But the two leaders did not publicly comment on the White House's decision to cancel the Keystone XL pipeline project, which would have boosted oil supplies from Canada's Alberta province to US refineries.
In a phone call two days after Mr Biden took office - Mr Biden's first official call as president - Mr Trudeau conveyed his "disappointment" at the pipeline decision. A US official later said the closure would "not be reconsidered".
Development of the pipeline was originally blocked by the Obama administration in 2015, but former President Donald Trump overturned that order and allowed it go ahead.
The project has been bitterly opposed by environmentalists and Native American groups for more than a decade. They see it as highly polluting and potentially a major setback to efforts to move away from fossil fuels.
Industry groups say it would create thousands of jobs and increase US energy security.
Earlier on Tuesday, US Press Secretary Jen Psaki told reporters Mr Biden had made clear to Mr Trudeau that the project was "not in the interests of the United States and that we want to try to address our climate crisis, while also creating good paying union jobs".
The US and Canada share one of the world's largest trade partnerships, and exchange close to $2bn (C$2.5bn/£1.4bn) in goods and services daily.
Smiles and promises of better days
It lacked much of the pageantry of an official bilateral meeting of leaders at the White House, but both Joe Biden and Justin Trudeau expressed optimism that US-Canadian relations were poised to take a turn for the better after Donald Trump's tumultuous four years in the White House.
"US leadership has been sorely missed over the past years," Trudeau told his American counterpart at the beginning of what was, essentially, a glorified video conference. He was speaking of the US's changed attitude toward climate change, but that kind of sentiment permeated the public portions of the day's events.
Trudeau had very publicly clashed with Trump, in a war of words conducted via duelling press releases and tweets. Now, Trudeau said, he was looking forward to working closely with the US again.
By the time the day was over, in their closing statements, Trudeau was referring to Biden as "Joe," and Biden was pledging to Trudeau - who towered on a massive screen beside him - that the US "has no closer and no more important friend than Canada".
The two nations still have notable differences - on trade and oil pipeline construction in particular - but at least for a day, it was all smiles and promises of better days to come.
What was said on China?
One major issue for both leaders is the Chinese detention of two Canadians, who have been accused of spying and held in jail since 2018.
Canada alleges that the men were arrested as retribution for the arrest of Huawei executive Meng Wanzhou on a US warrant.
Michael Spavor and Michael Kovrig were arrested in China in 2018 and formally indicted in June 2020.
Calling for their release in remarks following the meeting, Mr Biden said: "Human beings are not bartering chips. We're going to work together until we get their safe return."