Mattis: North Korea cannot drive wedge between the US and South Korea

"I know that people are watching for a wedge between South Korea, Republic of Korea, in other words and the United States," Mattis told reporters on a flight to Rome. "There's no wedge there, the military staffs are integrated. If you move up to the political level, Admiral Song, minister of defense Song, flew into Hawaii when I was out in the Pacific, that's so he and I could sit down face to face and consult."

Mattis' remarks come after South Korean President Moon Jae-in was presented a formal invitation to visit North Korea, potentially setting up the first meeting of Korean leaders since 2007.

The invitation was made by Kim Yo Jong, the younger sister of North Korean leader Kim Jong Un, during a historic meeting between North and South Korean officials at Seoul's presidential palace Saturday, presidential spokesman Kim Eui-kyeom said.

Moon responded to the invitation by suggesting the two countries "should accomplish this by creating the right conditions," adding that talks between North Korea and the United States were also needed, and requested that North Korea be more active in talking with the US, according to the spokesman.

Kim attended the opening ceremonies of the 2018 Winter Olympics in Pyeongchang, sitting in the same box as the Moon and US Vice President Mike Pence. Pence, who led the US delegation to the Olympics, has accused Pyongyang of using the event for its own ends.

"We will not allow North Korean propaganda to hijack the message and imagery of the Olympic Games," he said in Japan earlier this week.

Despite Pence's hardline stance and words, he has also signaled the United States is possibly open to negotiations when he said in regards to the North Korean officials, "I haven't requested any meeting. But we'll see what happens."

Mattis showed skepticism in calling these meetings a sign of progress between the two neighboring countries.

"I don't know if it's a sign, it's too early for me to tell what he'll do because in the midst of all this he ran a military parade that highlighted his ballistic missiles," Mattis said. "That's a very strange time if in fact he's trying to throw a warming to the country that he has attacked repeatedly."