The Obama administration on Tuesday refused to offer comments on a reported visit by former president Jimmy Carter to the Democratic People's Republic of Korea (DPRK) for the release of a U.S. man detained there, saying Washington has no plan to send envoy to Pyongyang.

"We will continue to withhold comment. We do not want to jeopardize the prospects for Mr. Gomes to be returned home by discussing any details related to private humanitarian efforts to get him released and back here safely to the United States," U.S. State Department spokesman Philip Crowley told reporters.

Reports said former president Jimmy Carter will visit Pyongyang in the coming days to negotiate the release of Aijalon Mahli Gomes who was detained by the DPRK on Jan. 25, 2010 for entering the country illegally. On April 6, Gomes was sentenced to eight years' imprisonment and a fine of about 700,000 U.S. dollars.

Crowley reiterated that the administration would not send a special envoy to the DPRK for the release of Gomes, whose healthy situation reportedly has been worsening, adding that the United States will continue evaluate Gomes' situation through Swedish diplomats there to negotiate the release with Pyongyang.

Sweden represents U.S. interest in Pyongyang in the absence of diplomatic relations.

"There are one instance in particular where through a private humanitarian mission we were able to secure the release of two journalists held captive in North Korea," said Crowley, referring to a private visit by former president Bill Clinton to Pyongyang last August for the release of two U.S. journalists detained there for illegal entry.

Laura Ling and Euna Lee, who worked for the Current TV co- founded by former vice president Al Gore, were captured in March, 2009, for illegally crossing the DPRK border from China and were sentenced to 12 years of hard labor in June.

Following Clinton's visit, in which he met with the DPRK's top leader Kim Jong-Il, Pyongyang announced the release. Analysts said Pyongyang wanted to use the journalists as chips to explore a direct dialogue mechanism with Washington for improving their relations.

The Obama administration, however, has claimed that any dialogue should be conducted in the Pyongyang's denuclearization process guided by the six-party talks mechanism, which participated by the two countries, China, the Republic of Korea, Japan and Russia.