North Korea’s nuclear weapons and ballistic missile programmes have been condemned by the G8 foreign ministers in the “strongest possible terms”.
Tensions have risen on the Korean peninsula in recent weeks.
In a communiqué, the ministers also expressed their “deep concern” at the toll of the conflict in Syria.
They also endorsed what they called a historic pledge on preventing sexual violence in conflict.
The G8 nations comprises the US, Britain, France, Germany, Italy, Japan, Canada and Russia.
Britain currently holds the rotating chairmanship of the G8 and the talks in London are a prelude to the annual G8 summit later this year in Northern Ireland.
Correspondents say Japan, present at the talks, had been looking for a strong statement of solidarity over Korea.
North Korea has been making bellicose threats against South Korea, Japan and US bases in the region.
The G8 ministers reportedly pledged to work to end violence in conflict, calling for urgent action to address “comprehensively” the “culture of impunity” in conflict zones.
“There is no disagreement with the United States over North Korea,” Russian Foreign Minister Sergei Lavrov said at a meeting with US Secretary of State John Kerry in London on Wednesday.
South Korea has raised its alert level amid indications that the North is preparing for a missile test.
Pyongyang has moved two Musudan missiles to its east coast. Estimates of the ballistic missile’s range vary, but some suggest it could be as high as 2,500 miles.
A missile therefore has the potential of hitting US bases on Guam, although it is not known whether the Musudan has been tested before.
There is also no evidence North Korea has miniaturized a nuclear weapon sufficiently to be used on a ballistic missile.
Correspondents point to Monday – the birthday of North Korea’s founder Kim Il-sung – as a potential launch date.
North Korea has increased its fiery rhetoric following fresh UN sanctions imposed after its third nuclear test and joint military manoeuvres by the US and South Korea.
Key North Korean anniversaries:
- 11 April – Kim Jong-un elected first secretary of the Workers’ Party and late father Kim Jong-il named General Secretary for Eternity in 2012
- 13 April – Kim Jong-un appointed first chairman of the National Defence Commission in 2012
- 15 April – Birthday of state founder Kim Il-sung (1912-1994)