Former US President Jimmy Carter has no immediate plans to visit North Korea, US officials and his aides said Monday, refuting media reports that he may go there again on a mission to free a Korean-American man imprisoned in the communist nation for nearly nine months.

Speculation has grown that Carter might go to Pyongyang soon since he met with US Secretary of State John Kerry in Washington last week, reports South Korea's Yonhap News Agency.

"North Korea was one of the topics that was discussed," State Department spokeswoman Jen Psaki said at a press briefing, adding, "And certainly he didn't indicate he was going at the time because it sounds like he didn't have plans to go."

Psaki also said she is not aware of any plans for the United States government to send a special envoy to North Korea for talks on the release of Kenneth Bae, convicted by North Korea of unspecified hostile acts against the regime. He was arrested in November.

The Carter Centre also said Carter has no immediate plans to travel to North Korea.

"President Carter is in Bogata, Colombia, on a trip to help announce success in the fight against river blindness disease there," Deanna Congileo, a spokeswoman at the Atlanta-based centre, said in an emailed reply. "He is not in North Korea. He has no immediate plans to travel to North Korea."

Diplomatic sources here, however, said the door remains open for Carter to visit North Korea some day. Carter will be tempted to go there again if there is chance he can secure Bae's release, the sources said.

Carter also has an interest in meeting North Korean leader Kim Jong-un, added the sources.

North Korea has a track record of attempting to use detained Americans for domestic propaganda and as a tool to leverage Washington. The North's stated goal is direct high-level talks with the Barack Obama administration.

Carter last visited North Korea in April 2011 along with a few other members of The Elders, an independent group of global leaders dedicated to peace. He failed to meet then-North Korean leader Kim Jong-il.

At that time, South Korean government officials disapproved of the trip, which they regarded as fruitless. Carter's group was merely misused by the North Koreans for propaganda, critics claimed.

In 2010, however, Carter won plaudits when he negotiated the release of American national Aijalon Gomes, sentenced to eight years of hard labour for illegally crossing into the North from China.

Carter, US president from 1977 to 1981, is known for his efforts to promote peace on the Korean Peninsula and around the world. He was awarded the 2002 Nobel Peace Prize.

Meanwhile, the State Department reaffirmed that it is continuing efforts toward Bae's release.

"This is an issue that we've been very engaged with over the course of time through our protecting power," Psaki said, referring to the Swedish Embassy in Pyongyang. The US has no consular office in North Korea as the nations have no formal diplomatic ties.

"We continue to urge North Korean authorities to grant Mr. Bae amnesty and immediate release," she said.