When asked if he was confident about the safety of the U.S.-Canada border, Trump said, "You can never be totally confident."
Trump later said that there are "many, many problems" that he has learned about in more detail since assuming office, adding that North Korea is a "big, big problem" but that "we have problems [in] just about every corner of the globe."
Trudeau would not criticize the decision by the U.S. to stop accepting Syrian refugees.
"The last thing Canadians expect is for me to come down and lecture another country," Trudeau said, adding that instead he will try to "be a positive example in the world."
"Our two nations share much more than a border. We share the same values. We share the love, the truly great love of freedom," Trump said.
Trump said that "both of our countries are stronger when we join forces" and that the U.S. is "deeply fortunate to have a neighbor like Canada."
"We should coordinate closely, and we will coordinate closely to protect jobs in our hemisphere and to keep wealth on our continent and to keep everyone safe," he said.
Trudeau said the two countries have a "deep, abiding respect for one another" and "that's a good thing because, as we know, relationships between neighbors are pretty complex."
Trudeau is the third foreign leader to meet with Trump at the White House.
Earlier today, Trump and Trudeau released a joint statement before the news conference, noting that they "recognize the security of our borders as a top priority."