New North Korean foreign minister was its disarmament negotiator

Ri Yong Ho, 59, replaces Ri Su Yong, who has been one of the highest-profile officials of a country whose current leader, Kim Jong Un, has not traveled abroad since taking power following the death of his father in 2011.

Ri Yong Ho, most recently vice foreign minister, represented North Korea at six-party talks on North Korea's nuclear program, which fell apart after their last round in 2008.

China, Japan, Russia, South Korea and the United States were the other parties to the talks.

Ri, a former ambassador to Britain, is likely to be responsible for making North Korea's case at the United Nations.

The U.N. Security Council in March imposed tough new sanctions against North Korea in response to its fourth nuclear test in January and the launch of a long-range rocket the next month.

North Korean state media has not announced Ri's appointment but North Korea's embassy in Britain informed the British Foreign Office of his appointment in a note dated May 16, and seen by Reuters on Tuesday.

North Korea has been isolated for decades but recently even its main ally, China, has been growing increasingly frustrated with it over its nuclear ambitions, which China disapproves of.

China backed the tighter U.N. sanctions in March.

The U.N. Human Rights Council has also adopted by consensus a resolution condemning North Korea's human rights record.

Lee Ji-sue, a North Korea expert at South Korea's Myongji University, said the change at the ministry did not signal a North Korean change in approach.

"Like Ri Su Yong who took orders from Kim Jong Il and Kim Jong Un, Ri Yong Ho won't have much say in foreign policies," he said. Kim Jong Il was the current leader's father.

Outgoing foreign minister Ri, 76, a well-travelled career diplomat, was named a member of the politburo during a recent congress of the ruling Workers' Party.