LOS ANGELES -- The pro-trade message Canada is touting in the United States will resonate with everyday Americans and their political class, even if the words get obscured by the breaking news of the day, Prime Minister Justin Trudeau says.

Standing at the Griffith Observatory in the Los Angeles hills -- a site made famous as a setting in multiple movies -- Trudeau said his pitch to save the North American Free Trade Agreement from falling apart was well received.

Behind Trudeau, a cloudy California sky obscured the city's most famous message: the Hollywood Sign.

Local coverage of the prime minister's visit to California has focused on U.S. President Donald Trump's talk and actions on immigration, a particularly acute issue in this "blue" state on the border with Mexico and home to the largest population of Canadians outside of Canada, some 150,000 people.

And Trudeau's talk Friday night at the Ronald Reagan library was overshadowed with international headlines about a crash between an SUV and a motorcycle officer in the prime minister's motorcade. The California Highway Patrol officer broke his clavicle in the accident.

Trudeau said Canadians needed to continually remind Americans about the bilateral relationship between the two countries, which can often be taken for granted.

"The conversations I've had across this country over these past few days have been extremely positive," the prime minister said on Saturday morning.

"Maybe it's not as breaking news as something else might be, but that emphasis that we are working together for the betterment of our citizens is a message that does continue and does resonate."

A weekend hike through Griffith Park marked the last public event for Trudeau on his four-day trip through the United States, where he hit communities that swung Democrat in the last presidential election to talk trade.

He met with governors and mayors as part of an ongoing charm offensive to win over states and cities on the merits of trade to pressure the White House. Congressional lawmakers were supposed to be at Trudeau's speech Friday night at the Reagan library in Simi Valley, outside Los Angeles, but a brief government shutdown forced them all to stay longer in Washington and miss the event.

Los Angeles mayor Eric Garcetti said the content and the timing of the speech were critical for Americans to hear through the white noise of other domestic issues.

"We can talk about the fights, but we're a family. Canada and Mexico are our two closest friends," Garcetti said.

"We really have a depth of relationship that isn't just about one visit."

California sells some $25.4 billion in goods and services to Canada, and almost 1.2 million jobs in the state rely on trade, according to federal statistics.

But it is also a forerunner for Canada in terms of legalizing marijuana, which came into effect at the start of the year. San Francisco has decided to provide amnesty for marijuana convictions going back decades in a move that other jurisdictions are following.

The Liberals have been threatened with legal action if they don't move faster on wiping clean simple possession convictions that have disproportionately affected black Canadians.

Trudeau indicated his government was in no rush to deal with amnesty ahead of when the new legal cannabis regime takes effect.

"Until we actually change the laws, the existing laws remain in place," Trudeau said.

"After we change the law, we will then look at steps forward on how we move on pardons and retroactive measures."