President Donald Trump speaks as he stands with Tony Kim, second left, Kim Dong Chul, center right, and Kim Hak Song, right, three Americans detained in North Korea for more than a year, after they arrived at Andrews Air Force Base in Md., Thursday, May 10, 2018. Vice President Mike Pence, left, and Secretary of State Mike Pompeo, second from right, listen. (AP Photo/Susan Walsh)

President Donald Trump announced Thursday that his summit with North Korean leader Kim Jong Un will occur June 12 in Singapore, the most significant step yet in his bid to rid the region of nuclear weapons.

Trump made the announcement via Twitter just hours after welcoming home three Americans held captive for more than a year in North Korea.

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

Trump had previously floated other possible locations, including the demilitarized zone between North Korea and South Korea.

The event will be the first meeting between a sitting U.S. president and a North Korean leader.

Trump has spoken in increasingly positive terms about the summit, while cautioning that he is prepared to walk away if progress isn’t being made. At the top of the agenda will be North Korea’s nuclear program. Trump has said any deal will have to include the denuclearization of the rogue nation.