President Donald Trump said he has the responsibility to do what his predecessors failed to do—bring peace to a nuclear-free Korean Peninsula.

Trump talked about numerous issues with German Chancellor Angela Merkel during a joint press conference Friday at the White House a day after the historic meeting between North Korean dictator Kim Jong Un and South Korean President Moon Jae-in.

“I think I have a responsibility,” Trump said. “I think other presidents should have done it. I think the responsibility has fallen on the shoulders of the president of the United States. I think I have a responsibility to see if I can do it.”

Trump reiterated that he is willing to “walk out” if he can’t reach a legitimate deal.

“If I can’t do it, it will be a very tough time for a lot of countries and a lot of people,” Trump said. “It certainly is something that I hope I can do for the world. This is beyond the United States. This is a world problem and it’s something I hope I’m able to do for the world.”

Trump said his meeting with Kim will be in the “coming weeks,” but declined to answer a question about whether he has spoken with him.

“We get a kick every once in a while out of the fact that I’ll be watching people that failed so badly over the last 25 years explaining to me how to make a deal with North Korea. I get a big, big kick out of that,” Trump said.

Merkel praised Trump for the negotiations.

“Today, we meet at a point in time where it has become very clear that the strength of the American president, where he really saw to it that the sanctions against North Korea are respected, has opened new possibilities, opened new ways,” Merkel said.

Trump also took a question about the moving of the United States Embassy in Israel to the Jerusalem capital. He said he “may go” to the opening.

Trump said the original cost for building the embassy in Jerusalem was going to be $1 billion, but it ultimately will be a few hundred thousand and built sooner. But, he said, “it’s going to be beautiful.”