U.S. President Donald Trump has hinted at the imminent release of Americans detained in North Korea, just weeks ahead of a planned summit between him and the North's leader, Kim Jong Un.

"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!" Trump wrote Wednesday on Twitter.

The U.S. government said it is looking into reports that the three Americans had been relocated from a labor camp to a hotel near Pyongyang ahead of the Kim-Trump summit.