((This Dec. 5 story corrects year in 2nd paragraph to 2011 from 2012))
By Michelle Nichols and David Brunnstrom
UNITED NATIONS/WASHINGTON (Reuters) - United Nations political affairs chief Jeffrey Feltman arrived in North Korea on Tuesday for a rare visit that some analysts and diplomats hope could spark a U.N.-led effort to defuse rising tensions over Pyongyang's nuclear and missile programs.
The former senior U.S. State Department official is the highest-level U.N. official to visit North Korea since 2011. During a four-day visit he is due to meet Foreign Minister Ri Yong Ho to discuss "issues of mutual interest and concern."
"This is broadly a policy dialogue with (North Korea). I think we have to wait and see what comes out," U.N. spokesman Stephane Dujarric told reporters on Tuesday. "All key member states ... were informed and briefed of the visit."
U.N. Secretary-General Antonio Guterres told Russia, Japan, the United States, China and North and South Korea in August he was available to help broker talks. So-called six-party talks on North Korea's nuclear program stalled in 2008.
A U.N. official, speaking on condition of anonymity, described expectations for Feltman's visit as "modest and high at the same time, meaning that they depend on what our hosts are thinking as well."
"We need to find a way to scale back tensions," the official said. "I don't think we will have a major breakthrough being announced at the end of this trip. But the visit could serve as a step to build a framework for engagement."
Suzanne DiMaggio of the New America Foundation think tank, a participant in recent unofficial talks with North Korea, said Feltman could propose during his visit to Pyongyang that Guterres play a mediation role.
"I do think that the Trump administration would like to explore talks about talks at this stage. I think the North Koreans are assessing the timing of when to do that," she told a seminar in Washington on North Korea.
State Department spokeswoman Heather Nauert said Feltman was not traveling on behalf of the U.S. government.
"And he's not traveling - I want to make this clear - with any kind of message from the U.S. government ... He's going on behalf of the U.N., not the U.S. government," she told a regular news briefing.
Nauert said Washington remained open to talks if North Korea showed it was serious about giving up its nuclear weapons, but added: "The activities they have been engaged in recently have shown that they are not interested, they are not serious about sitting down and having conversations."
North Korea has been working to develop nuclear-tipped missiles capable of reaching the United States in defiance of U.N. sanctions. It conducted its sixth and largest nuclear test in September and last week tested a missile capable of reaching anywhere in America.
Feltman told the 15-member Security Council last week that its unity "creates an opportunity for sustained diplomatic engagement – an opportunity that must be seized in these dangerous times to seek off-ramps and work to create conditions for negotiations."
In September, Russian U.N. Ambassador Vassily Nebenzia urged a return to dialogue, including "by leveraging mediation efforts" by Guterres.
Russian Deputy Foreign Minister Igor Morgulov said on Tuesday that Pyongyang was seeking dialogue with Washington on its nuclear program, according to RIA news agency. Morgulov, at a conference in Berlin, was quoted as saying Russia had communication channels with North Korea open and was ready to exert its influence on Pyongyang.
Sweden's Deputy U.N. Ambassador Carl Skau told reporters he hoped Guterres could mediate in "probably the largest threat to international peace and security at the moment."
Britain's Deputy U.N. Ambassador Jonathan Allen said Feltman had "our backing and I think he goes to represent the U.N. family as a whole."
(Reporting by Michelle Nichols)