Prime Minister Justin Trudeau's arrival at the White House sparked a flurry of activity on Twitter, as Americans reacted to the PM and his friendly encounter with U.S. President Barack Obama.

The two leaders appeared happy and at ease when they appeared on the White House lawn Thursday morning. Obama casually joked about Canada-U.S. differences in his welcoming speech, saying there are some things the two nations will never agree on, such as "whose beer is better," and "who's better at hockey."

"Don't get me started," Trudeau said as he stood beside Obama.

"Where's the Stanley Cup right now?" Obama fired back. "I'm sorry, is it in my hometown right now, with the Chicago Blackhawks?"

When his turn came at the podium, Trudeau ad-libbed a joke of his own, saying that Americans enjoy many exports from Canada, "including Jonathan Toews, Duncan Keith and Patrick Sharp of the Chicago Blackhawks."

As a few hockey fans were quick to point out on Twitter, however, Trudeau misspoke in that Sharp is no longer a member of the Blackhawks. He was on Chicago's Stanley Cup-winning team last year, but was traded to the Dallas Stars last summer.

Obama remarked during his speech that he's "never seen so many Americans excited by a visit from a Canadian prime minister."

As Trudeau delivered his opening remarks, some on Twitter said they had crushes on Canada's "hot" PM, while others declared the fledgling Trudeau-Obama relationship a "bromance" in the making.

First lady Michelle Obama and Sophie Gregoire Trudeau had some fun of their own later in the morning, at a press conference for Obama's Let Girls Learn charitable initiative. Obama said Gregoire Trudeau was like her "soulmate," and joked that "we're going to be in a lot of trouble before this visit is over."

Obama praised Gregoire Trudeau for having a "great sense of humour," and described the youngest Trudeau boy, Hadrien, as "the delicious one" with "lots of curly hair."

"Pudgy. You can say pudgy," Gregoire Trudeau added.

It wasn't the only bit of attention Hadrien garnered on the trip.