Trump Becomes First Sitting U.S. President To Step Into North Korea.

President Donald Trump made history by becoming the first sitting U.S. President to walk across the border into North Korea. And it was all set up in a tweet.

In a tweet, Trump announced he would meet North Korean leader Kim Jong Un at the DMZ, the demilitarized zone or border that separates North Korea from South Korea.

Hours later, on Sunday, June 30, Trump met North Korean leader Kim Jong Un inside the DMZ and shook hands before Trump stepped across the border from Panmunjom, South Korea into North Korea.

"Good to see you again. I never expected to meet you at this place," a translator quoted Kim, as the two men shook hands. Then Kim invited Trump to step across the border, telling him, "You are the first U.S. president to cross the border."

Photographers jockeyed for position at the Demarcation Line to record history when Trump walked into North Korea early Sunday morning. The epic moment briefly united Democrats and Republicans back in the U.S.

Many U.S. lawmakers said the meeting between the two world leaders was a positive move toward world peace. They hoped the meeting would restart stalled nuclear disarmament talks.

Afterwards, Trump and Kim turned and walked back across the border to the South Korean side where they spoke with South Korean leader Moon Jae-in. Then Trump and Kim met for an hour behind closed doors.

The White House released a transcript of the meeting in which Trump and Kim said they are committed to the "complete denuclearization" of the Korean peninsula.

Trump's advisor Ivanka Trump and her husband, U.S. Senior Advisor Jared Kushner were there to witness history.