WASHINGTON (Reuters) – U.S. President Donald Trump said on Thursday he will meet with North Korean leader Kim Jong Un on June 12 in Singapore for a first ever summit between the leaders of the two countries.

“The highly anticipated meeting between Kim Jong Un and myself will take place in Singapore on June 12th. We will both try to make it a very special moment for World Peace!” Trump said on Twitter.

The two leaders are expected to discuss North Korea’s nuclear weapons development and testing program, which has deepened long-seated tensions between Washington and Pyongyang.

Trump’s announcement came just hours after three Americans who had been held prisoner in North Korea arrived at a U.S. military base outside Washington, having been released by Kim.

Trump said on their arrival that he believed Kim wanted to bring North Korea “into the real world” and had high hopes for their planned meeting, which would be the first between a serving U.S. president and a North Korean leader.

“I think we have a very good chance of doing something very meaningful,” Trump said. “My proudest achievement will be – this is part of it – when we denuclearize that entire peninsula.”

(Reporting by Doina Chiacu; Editing by Chizu Nomiyama and Alistair Bell)