The United States should be putting enough pressure on North Korea to give up its nuclear weapons by strengthening American allies in the region, but President Donald Trump is doing just the opposite, Rep. Seth Moulton said Friday.

"We should be talking about a Pacific NATO to help contain China and put pressure on North Korea," the Massachusetts Democrat told MSNBC's "Morning Joe." "But the president is doing the exact opposite. He's just cozying up to Kim Jong Un at this point...he's becoming best friends with our enemies and leaving our allies out to dry," said Moulton.

The lawmaker also told the program that he's "seriously" considering a run for the 2020 presidential nomination.

"It's going to take a new generation of leadership," said Moulton. "It's going to take someone who cannot only beat Donald Trump but who can bring the country back together again when Trump is gone. That's why I'm taking a serious look at this race."

But beating Trump won't mean trying to "out-Trump Trump," said Moulton, a veteran of the war in Iraq.

"You've got to put the president in his place and then talk about what you're going to do for the country," said Moulton. "Taking on Donald Trump is hard. He is resonating in a lot of parts of the country. We've got to acknowledge that as Democrats. I don't think it's a simple thing to beat him. I was a platoon commander in Iraq. It won't be the toughest thing I've ever done."