South Korean President Lee Myung-Bak Monday called on North Korea to renounce nuclear weapons, saying Pyongyang would be invited to next year's nuclear security summit if it agreed to do so.

"This is an official proposal to North Korea," Lee told a joint press conference here with German Chancellor Angela Merkel.

"North Korea must say it will renounce nuclear weapons. When it has promised to do so, then we shall be able to issue an invitation" to next year's nuclear security summit taking place in South Korea, Lee said.

South Korea had earlier said the North should first apologise for recent military provocations in order to be invited to the summit.

Lee was in Berlin at the start of a week-long visit to Germany, Denmark and France aimed at cementing ties ahead of the introduction, next month, of a sweeping free trade pact between his country and the European Union.

Under the pact, the two sides will axe 98 percent of customs duties within five years, apart from those on a few Korean farm products.

At the last nuclear security summit, held in Washington in April 2010, 47 world leaders agreed to lock up the world's most vulnerable nuclear materials within four years to prevent terrorists from setting off a global "catastrophe."

Earlier Monday Lee went for a walk-about at the Brandenburg Gate, a monument in the centre of the German capital which, because of its setting right on the Berlin Wall, used to symbolize the division of the Germany between East and West during the Cold War. Germany was reunified in 1990.

earlier related report
Japan nuclear envoy to visit S. Korea this week
Seoul (AFP) May 9, 2011 - Japan's chief envoy to stalled multinational nuclear disarmament talks will visit South Korea this week to coordinate policy toward North Korea, the foreign ministry said Monday.

Japanese envoy Shinsuke Sugiyama is to arrive in Seoul Tuesday for a two-day trip and meet his South Korean counterpart Wi Sung-Lac Wednesday, the ministry said.

Six-party talks on ending the North's nuclear programmes in return for diplomatic and economic benefits have been stalled since December 2008.

The North fuelled regional security fears last November by disclosing an apparently functional uranium enrichment plant, which could give it a second way to make atomic bombs in addition to its plutonium stockpile.

Pyongyang has expressed interest in restarting the six-party forum that also involves China, the United States and Russia. But Seoul and Washington say it should first show it is serious about disarmament and mend cross-border ties.

Former US president Jimmy Carter visited North Korea last month and said the communist regime was ready for peace talks with the democratic South, but the Seoul government questioned Pyongyang's sincerity.

Inter-Korean relations have been icy since Seoul accused Pyongyang of torpedoing a warship in March 2010 with the loss of 46 lives. The North denies the charge but shelled a South Korean border island last November, killing four people.