WASHINGTON, U.S. President Donald Trump announced Wednesday that three American detainees have been released from North Korea and that the date and venue of his summit with North Korean leader Kim Jong-un have been set.

"I am pleased to inform you that Secretary of State Mike Pompeo is in the air and on his way back from North Korea with the 3 wonderful gentlemen that everyone is looking so forward to meeting. They seem to be in good health," Trump tweeted.

"Also, good meeting with Kim Jong Un. Date and Place set," Trump said.

Trump said Pompeo and the detainees will be arriving at Andrews Air Force Base at 2 a.m. Thursday.

"I will be there to greet them. Very exciting!" Trump said.

The North's release of the three Korean Americans, who have been held for as long as two years and seven months, is a goodwill gesture designed to show Trump ahead of the summit that the North is serious about improving relations with the U.S.

The three men -- Kim Hak-song, Tony Kim and Kim Dong-chul -- were detained in North Korea on charges of espionage or "hostile acts" against the regime.

The planned meeting between Trump and Kim heightened expectations for their release.

Pompeo flew to Pyongyang Tuesday to prepare for the unprecedented summit. It was his second trip there since Easter weekend.

Trump has said he will sit down with Kim late this month or early next month to discuss the dismantlement of the regime's nuclear weapons program.

Possible sites include the Demilitarized Zone dividing the Koreas, and Singapore.

North Korea has previously used American detainees as leverage to force the U.S. to deal with the regime. The two countries have not established formal diplomatic ties.

Former U.S. President Bill Clinton visited the North in August 2009 in a private capacity to bring home two American journalists detained in the country.

Another former U.S. president, Jimmy Carter, made a trip to Pyongyang in August 2010 to win the release of Aijalon Mahli Gomes, a U.S. citizen who was held in the communist state for about seven months.

In November 2014, James Clapper, former director of National Intelligence, made a secret visit to the North to bring home two detained Americans, Kenneth Bae and Matthew Miller.

Most recently, then top U.S. nuclear envoy Joseph Yun visited Pyongyang in June to win the release of American college student Otto Warmbier. He was found in a coma and died shortly after returning home.

"President Trump appreciates leader Kim Jong Un's action to release these American citizens, and views this as a positive gesture of goodwill," the White House said in a statement. "The three Americans appear to be in good condition and were all able to walk on the plane without assistance. All Americans look forward to welcoming them home and to seeing them reunited with their loved ones."

En route from Pyongyang, Pompeo said the date and location of the Trump-Kim meeting could be announced in the next few days, according to Reuters. The two sides have been having good and productive talks to lay the groundwork for the summit, which is expected to be a one-day meeting, he was quoted as saying.

The State Department said Pompeo and Kim had a "productive discussion on a range of issues," including the upcoming summit, and the secretary is "delighted" to bring the three Americans home.

Pompeo flew into Pyongyang shortly after Kim returned home from another unannounced visit to China, where he had his second summit with Chinese President Xi Jinping in about 40 days and reportedly reaffirmed his commitment to the denuclearization of the Korean Peninsula.

The Kim-Xi meeting underscored the two countries' tight alliance as diplomacy has moved rapidly toward efforts to denuclearize the regime.

The Trump administration says its aim is the complete, verifiable and irreversible dismantlement of the North's nuclear program. Kim, meanwhile, has insisted on a phased and synchronized approach that would likely see an easing of sanctions against the regime in exchange for incremental steps toward denuclearization.

"We're not going to relieve sanctions until such time as we achieved our objectives," Pompeo said Tuesday. "We are not going to do this in small increments, where the world is essentially coerced into relieving economic pressure."

The flurry of diplomacy began this year after Kim expressed an interest in sending a delegation to the PyeongChang Winter Olympics in South Korea in February. Inter-Korean relations have improved rapidly in the months since then and led to a historic summit between South Korean President Moon Jae-in and Kim last month. The two leaders agreed to pursue "complete denuclearization" of the peninsula and a peace treaty to formally end the 1950-53 Korean War.

Source: Yonhap News Agency