Generals from North Korea and the US-led UN Command in South Korea met for talks Monday for the first time in almost seven years as tensions rise over Pyongyang's planned rocket launch.

Their meeting at Panmunjom, inside the frontier buffer zone, came two days after the communist North warned US troops to stop "provocations" in the area or face retaliation.

The United Nations Command said they discussed ways to ease tensions during the 32-minute meeting, which was requested by the North, and agreed to further talks.

It welcomed the dialogue, saying it could build trust.

Yonhap news agency said the North renewed its condemnation of a major joint US-South Korean military exercise due to start March 9. A UN Command spokesman declined to confirm the report.

Fears of a border clash have grown after the North scrapped peace accords with Seoul and warned of war. It is angry at South Korea's conservative leader Lee Myung-Bak, who scrapped his predecessors' policy of offering virtually unconditional aid to Pyongyang.

The North is also preparing to fire a rocket for what it calls a satellite launch, although Seoul and Washington say the real purpose is to test a missile which could theoretically reach Alaska.

Russian Foreign Minister Sergei Lavrov also questioned the launch and called for "restraint".

"No one forbids anyone to launch satellites, but on the other hand, we must understand what kind of missile this is," Lavrov said.

Stephen Bosworth, the new US envoy on North Korea, was due in Beijing on Tuesday where he will meet "senior officials", a State Department spokesman said.

"He will then visit Tokyo and Seoul and will consult with Russian officials, who will travel separately to the region," said spokesman Gordon Duguid.

The South Korean and Japanese foreign ministers, Yu Myung-Hwan and Hirofumi Nakasone, spoke by telephone Monday.

They agreed a rocket launch for any reason would violate a UN resolution passed after the last missile test in 2006, Seoul's foreign ministry said.

A US-led UN force fought for South Korea in the 1950-53 war. The United States still stations 28,500 troops there to back up the South's 680,000-strong military against the North's 1.1 million-member armed forces.

A US aircraft carrier and 26,000 US troops, plus an undisclosed number of Seoul's troops, will take part in next week's annual drill. Seoul and Washington say it is purely defensive, but Pyongyang calls it a preparation for war.

"North Korea filed lengthy complaints against the plan to hold the... exercise and the situation involving the US military deployment on the Korean peninsula," Yonhap quoted a source as saying.

There was no tangible agreement on reducing tension, the source added.

A UN Command statement said that both sides "discussed measures to reduce tensions and introduce transparency" and agreed to hold more talks.

"The UNC welcomed this discussion with North Korea which holds the prospect for building trust and preventing misunderstandings between both sides," it quoted delegation chief, US Air Force Major General Johnny Weida, as saying.

On Saturday, the North's army accused US forces of "behaving arrogantly" inside the Demilitarised Zone, which extends for two kilometres (1.2 miles) on each side of the borderline.

The North, threatening an unspecified "resolute counter-action", said US military personnel had approached close to the borderline on 66 occasions this year.

South Korea's defence ministry said they had been engaged in "legitimate" monitoring in the South's side of the zone.

Unification Minister Hyun In-Taek again offered the North dialogue in a speech marking the 40th anniversary of the founding of his ministry, which handles cross-border relations.

But Pyongyang blasted "traitor Lee Myung-Bak" for refusing to honour summit pacts between the North and his predecessors.