Canada and the United States make history when they work together, Prime Minister Justin Trudeau said as he wrapped up his official visit to Washington, a trip he called productive and "a tremendous success."

After being honoured with a state dinner at the White House Thursday night, Trudeau spent Friday honouring the war dead, talking to university students and attending a luncheon where he made remarks and took questions.

Speaking to the lunchtime audience hosted by Canada 2020 and the Center for American Progress, two think-tanks, Trudeau reflected on his trip and said some parts, like the glamorous black-tie dinner, were "undeniably fun."

Others, like his visit to Arlington National Cemetery, were moving, the prime minister said, and overall he expressed satisfaction with what was accomplished on the trip.

"We came here to get things done. And on that front, our time here in Washington has been a tremendous success," said Trudeau.

Trudeau highlighted the agreements he and U.S. President Barack Obama reached to tackle climate change, protect the Arctic and address border-related measures that will ease the movement of people and goods.

Even though Obama is on his way out of the White House and the U.S. will have a new president after the November election, Trudeau predicted the agreements will be long-lasting.

"I'm optimistic about the work we've done over the past few days, I'm optimistic that it will continue to pay dividends well into the future," he said.

He also talked about how optimism is a key element that's needed for progressive politics in both countries.

"You see, fear is easy. Friendship? Friendship takes work. But Canada and the United States have proven, time and time again, that finding common ground is worth the effort," Trudeau said.

"On our own, we make progress. But together, we make history."

Winning with a positive message

Trudeau talked during the question-and-answer portion of the program about how he didn't want to run a campaign last fall that used negative ads, scare tactics or personal attacks. Canadians were growing tired of being cynical about politics, he told the audience.

Instead, he wanted to highlight differences in policy positions, he said. He talked about how he and Stephen Harper disagreed over stripping citizenship for those convicted of terrorism.

"That is a perfect narrative for the politics of fear and aggression, and yet it's me sitting here as prime minister of Canada and not Stephen Harper," he said.

Canada's relationship with U.S. 'strong, thriving'6:35

Trudeau was asked how he and progressives should respond to a rise of populism and xenophobia in the United States and elsewhere. He said the answer is not to tell people who are angry that they are wrong, but rather understand the reasons underlying their fears, anger and anxiety and then work together to face challenges.

Trudeau also talked about climate change, calling it the "defining issue of our time."

After the lunchtime event, Trudeau dropped by the World Bank and met with its president Jim Yong Kim and staff. Kim wrote on Twitter that he commends Trudeau for his leadership on climate change and the Syrian refugee crisis.

A crowd of patriotic Canadians who work at the bank gathered to see the prime minister and welcomed him by singing O Canada

Trudeau also spoke to staff at the Canadian Embassy before leaving Washington shortly after 6 p.m. ET. 

Canada - U.S. trade: what's at stake?9:06

Honouring war dead

Trudeau's final day in Washington began by honouring America's war dead at historic Arlington National Cemetery in Arlington, Va., just across the Potomac River from Washington.

Trudeau took part in a wreath-laying ceremony at the tomb of the unknown soldier. The white marble sarcophagus sits atop a hill with a view of the U.S. capital.

The national anthems of the U.S. and Canada were played, and Trudeau paused for a moment of silence after laying the wreath. He then visited the Canadian Cross of Sacrifice, a monument dedicated to Americans who served with the Canadian military in the First World War, Second World War and Korean War.

Trudeau was accompanied by his wife, Sophie Grégoire-Trudeau, Defence Minister Harjit Sajjan, Foreign Affairs Minister Stéphane Dion and Canada's ambassador in Washington David MacNaughton.

Trudeau lays wreaths at Arlington National Cemetery1:34

Trudeau's morning also included an appearance at American University in Washington. In his opening remarks to students, Trudeau said meeting young people is something that "really matters to me."

'Focused on your future'

He said the work he and Obama did Thursday is focused on the coming decades.

"We are focused on your future," he told them.

Students eagerly lined up at microphones and asked questions on a range of topics including feminism, Canada's economy, its diversity, and its contribution to the fight against ISIS. Trudeau explained the decision to withdraw Canada's six fighter jets and instead ramp up other contributions to the U.S.-led coalition saying the shift in strategy "suits our best capabilities."

Trudeau told the students that the approach he and his team are taking to politics is a collaborative and respectful one that draws on positive instincts rather than fear and division.

Trudeau arrived in Washington Wednesday evening. On Thursday, there was an official welcoming ceremony on the south lawn at the White House, he met with Obama in the Oval Office and the two leaders held a news conference. Trudeau also spent some time on Capitol Hill.

The day was capped off with a star-studded state dinner at the White House, an honour that hadn't been given to a prime minister in 19 years.


​This weekend, listen to CBC Radio's The House with host Chris Hall on Saturday at 9 a.m. (9:30 in Newfoundland and Labrador) — or listen to the The House midweek podcast to get a preview now.