Foreign ministers from G8 countries shared their deep concerns over Pyongyang at a meeting in London on Thursday dominated by its war threats as well as the bloody conflict in Syria.

An expected missile launch by the Democratic People's Republic of Korea was first on the agenda, followed by discussions on Iran's nuclear program and Wednesday's fresh appeals from the Syrian opposition for weapons to fight President Bashar al-Assad, a British official said.

"Pyongyang's war rhetoric needs to end," Germany's Foreign Minister Guido Westerwelle said, adding that all of the group's ministers shared his conviction.

"This war rhetoric is not in any way acceptable and the G8 has a united position on this," he said.

US actress Angelina Jolie attended a session dedicated to sexual violence in conflict zones, which British Foreign Secretary William Hague has made a priority of his country's chairmanship of the Group of Eight rich nations this year.

The talks, which began with informal meetings and a dinner on Wednesday, have been dominated by the rising tensions on the Korean peninsula and efforts to address the conflict in Syria.

The Japanese foreign minister made clear in talks with US Secretary of State John Kerry on Wednesday his deep concerns about Pyongyang's increasingly threatening behavior.

Fumio Kishida said Japan is extremely concerned over Pyongyang's intention to restart nuclear facilities in Yongbyong, as well as the expected missile launch and threats made against the US and its allies, a Japanese official told Kyodo News.

Kerry is due to visit Seoul and Tokyo after he leaves Britain.

The G8 condemned a DPRK missile launch last year and despite divisions on other issues, is likely to agree on a similar response if this happens again, US officials say.

After talks with Kerry on Wednesday, Russian Foreign Minister Sergei Lavrov warned against exacerbating tensions with military maneuvers - although he did not identify which country he believed was carrying out such maneuvers.

"On North Korea we have no differences with the United States," Lavrov told reporters. "One just shouldn't scare anyone with military maneuvers, and there's a chance that everything will calm down."

On Syria, where the UN estimates that a two-year civil war has killed more than 70,000 people, Kerry met Syrian opposition leaders in London on Wednesday to discuss ways to step up non-lethal aid to the rebels.

Britain and France have been pushing for the European Union to lift or amend its arms embargo on Syria so weapons can be sent to rebel fighters.

Hague said this week that no decisions have been made on whether the UK will allow the embargo to expire as scheduled June 1, effectively clearing the way to arm the rebels. He said if the situation in Syria continues to deteriorate, there will be a strong case for amending or lifting the embargo.

AP-AFP