China kept silent on Friday about a reported visit by North Korea's secretive leader, Kim Jong-il, that analysts say appears intended to line up Beijing behind his dynastic succession plans. Coinciding with the unconfirmed trip, former U.S. President Jimmy Carter returned home from Pyongyang on Friday with an American, Aijalon Mahli Gomes, who was arrested in January and sentenced to eight years of hard labour for illegally entering North Korea. There was no indication that Carter met Kim. State media in the North said No. 2 leader Kim Yong-nam had told Carter that Pyongyang was committed to denuclearizing the peninsula and resuming stalled talks on its nuclear disarmament. There have been no firm sightings of the 68-year-old Kim Jong-il in China, who has appeared frail and gaunt since suffering a stroke in 2008. Kim may be seeking approval for succession plans from China, his beleaguered country's key economic and political backer, but Beijing is unlikely to shed any details as the two countries are deeply secretive about their dealings. It would be the second time since May that Kim has visited China.