The meeting between President Trump and French President Emmanuel Macron began with an odd moment, even given the rising tensions between Mr. Trump and U.S. allies over steel and aluminum tariffs the U.S. has recently implemented. Someone in the room, according to a pool reporter, asked the two men to arm wrestle/

"He'd be very tough to beat," Trump said. "He's my friend. We've had a great relationship right from the beginning."

The president said of Macron, "We've had really a very good relationship. Very special."

Get Breaking News Delivered to Your Inbox

"The United States has had a very big trade deficit," Mr. Trump also said. "Something's going to happen. I think it's going to be very positive." And, he added, "This is turning out to be a very interesting day," though he did not explain what he meant.

Macron said the two" had a very open and direct discussion," and he seemed optimistic about smoothing out their differences on trade. "On trade there is a critical path," he said. "I saw a willingness to find an agreement. And a win-win approach."

Mr. Trump reiterated that Russia's possible reinstatement as part of the G-7 countries with the largest economies hasn't been discussed. On Friday morning, as he departed the White House, the president had raised the idea that Russia should have a seat at the table. Russia was ousted from the group in 2014 because of its annexation of Crimea.

"Russia should be in this meeting. Why are we having a meeting without Russia being in the meeting? And I would recommend, and it's up to them, but Russia should be in the meeting, it should be a part of it," Mr. Trump said, adding that "they should let Russia come back in."

President Trump arrived late to the summit Friday afternoon, amid tensions with the strongest allies of the U.S. The president insists France, Canada, the European Union and other allies are ripping off America on trade.

"We're going to deal with the unfair trade practices," Mr. Trump said before departing Friday. "If you look at what Canada, Mexico, the European Union, all of them have been doing to us for many, many decades, we have to change it. And they understand it's going to happen."

During the summit, Mr. Trump said he thinks the relationship between the U.S. and Canada is probably better than it's ever been. Mr. Trump said they have made progress on trade, after blasting Trudeau on Twitter.

Only the day before the G7 summit, Mr. Trump had said, "Prime Minister Trudeau is being so indignant, bringing up the relationship that the U.S. and Canada had over the many years and all sorts of other things...but he doesn't bring up the fact that they charge us up to 300% on dairy — hurting our Farmers, killing our Agriculture!"