Kim Jong Un has chalked up a lot of firsts since taking power at the end of 2011: His country’s first hydrogen bomb test. Its first launch of an intercontinental ballistic missile . And the first crossing of the demilitarized zone by a North Korean leader since the Korean War.

He will rack up another one here Tuesday, when he becomes the first North Korean leader to meet with a sitting U.S. president. It will be the most important day to date of his expectation-defying reign.

“This is an epic-making moment,” said Ken Gause, an expert on North Korea’s leadership at CNA, a research group based in Virginia. “Even if this is just a meet-and-greet, it’s going to be a huge event simply because the president of the United States and the head of North Korea actually sat at the same table.”

Both leaders have a penchant for making bold decisions and a love of the limelight. Yet both want this meeting to be more than just a photo op.