* U.S. envoy Bosworth meets South Korean officials
* Bosworth heading to Beijing
* Six-party talks wanted, but success seen elusive
By Sylvia Westall
SEOUL, Jan 5 (Reuters) - The U.S. has stepped up pressure on China to rein in North Korea, sending its envoy to Beijing on Wednesday as part of a campaign to push the North to end its nuclear work.
The U.S. envoy for North Korea policy, Stephen Bosworth, met South Korean officials in Seoul before heading to China.
Washington hopes serious negotiations over North Korea's nuclear programme can start soon, though a breakthrough will prove difficult as the parties seek proof Pyongyang is serious about eventually disarming.
Tension on the Korean peninsula has spiked to some of its highest levels since the 1950-53 Korean War after last year's sinking of a Southern ship which killed 46 sailors, an exchange of artillery fire, nuclear revelations and threats of war from both sides.
President Barack Obama's national security adviser met China's foreign minister on Tuesday in Washington and discussed the North Korean issue.
Tom Donilon and Yang Jiechi discussed ways their countries could persuade North Korea to abandon nuclear weapons work and "avoid destabilizing behaviour", the White House said.
In Seoul, U.S. envoy Bosworth met South Korea's foreign minister and nuclear negotiator. Bosworth does not appear to be in the region to unveil a U.S. proposal to get the North back to negotiations, but said he is collecting views from all sides.
Asked on Wednesday whether the U.S. was putting pressure on Seoul to restart disarmament-for-aid talks with the North, the U.S., Japan, China and Russia, Bosworth said: "Never." He gave no further comment on his meetings.
Bosworth will arrive in China later on Wednesday, and visit Japan on Thursday.
The flurry of diplomatic activity comes ahead of a meeting between Obama and Chinese President Hu Jintao this month, when North Korea will be a central topic.
In recent days all sides have suggested they are willing to restart the six-party talks which collapsed over two years ago when North Korea walked out.
Pyongyang appears keen to return to the negotiating table where in the past it has won substantial aid after ratcheting up tensions. Seoul and Washington have said they first want to see proof of Pyongyang's commitment to a negotiated settlement.
"The Korean nation should defuse the confrontation between the north and the south at an early date," North Korea's official Rodong Sinmun newspaper said on Wednesday, according to quotes carried by state news agency KCNA.
Relations between the rival Koreas could not improve "as long as the said relations remain in the state of confrontation and on the brink of war without dialogue, contact and cooperation," it said.
Analysts say North Korea's provocations in 2010, and China's effective protection of it from serious consequences, left Washington, Seoul and Tokyo more closely aligned in policy than ever before, which may make it easier for them to approach Pyongyang.
Still, observers question whether North Korea, which has tested nuclear devices twice in recent years, will be prepared to give up its atomic work which it sees as a cornerstone of a "military first" policy, and a powerful bargaining chip for talks.
(Editing by Daniel Magnowski)