US Secretary of State Mike Pompeo will return from North Korean with three American Christians currently imprisoned in the country, according to South Korean official.

The official told South Korea's Yonhap News Agency that Pompeo was expected to return to the United States with a specified time and date for President Donald Trump's upcoming meeting with North Korean Dictator Kim Jong Un. In addition, Pompeo will return with the three American captives.

"We expect him to bring the date, time and the captives," the official said, while speaking on condition of anonymity.

Pompeo arrived in North Korea early Wednesday morning to prepare for the US-North Korea meeting.

Trump announced the visit Tuesday afternoon and hinted that Pompeo may return with three American Christians imprisoned in the Hermit Kingdom.

"Plans are being made, relationships are building," Trump told reporters at the same time he announced the United State's withdrawal from the Iranian nuclear deal. "Hopefully a deal will happen and, with the help of China, South Korea and Japan, a future of great prosperity and security can be achieved for everyone."

However, Trump remains cautious and added: "We'll see how it all works out - maybe it will, maybe it won't

The president also also expressed careful optimism about the potential release of the American Christians who are imprisoned in North Korea.

"We will soon be finding out," he said. "It would be a great thing if they are, we'll soon be finding out."

Trump also hinted at their release on Twitter last week.

"As everybody is aware, the past Administration has long been asking for three hostages to be released from a North Korean Labor camp, but to no avail. Stay tuned!" he said.

As everybody is aware, the past Administration has long been asking for three hostages to be released from a North Korean Labor camp, but to no avail. Stay tuned! — Donald J. Trump (@realDonaldTrump) May 3, 2018

Sources inside the Department of Defense told CBN News last week that Kim Dong-chul, Kim Sang-duk and Kim Hak-song were all moved from a labor camp early last month.

Sources also said they were being given health care and were resting.

Kim Dong Chul, a Korean-American missionary, has been imprisoned for the longest out of the three. He was arrested in October 2015 and sentenced in March 2016 to 10 years of hard labor for subversion.

Tony Kim, also known by his Korean name Kim Sang Duk, was arrested on April 22, 2017, just before boarding a plane for a flight back to the United States.

A month later, another Christian professor, Kim Hak Song, was arrested.

Both were arrested on suspicion of hostile acts.

Many activists hope the trio will return home before or during the President's meetings with North Korea.

"We believe that Mr. Trump can take them back on the day of the US-North Korea summit or he can send an envoy to take them back to the US before the summit," said Choi Sung-ryong, a leading activist