Updated

US Secretary of State John Kerry flew from tough Middle East peace talks into international meetings in Asia on Monday devoted to a full plate of sensitive issues including North Korea's nuclear programme and fugitive leaker Edward Snowden.

Kerry landed in Brunei to join foreign ministers from China, Japan, Russia, the European Union and across the Asia-Pacific for an annual security forum in which the focus has so far largely been on Chinese territorial claims.

One of Kerry's most closely watched meetings will take place Tuesday, when he holds one-on-one talks with Russian Foreign Minister Sergei Lavrov.

Washington is angry that Snowden, the former government contractor who is wanted by the United States after divulging details of widespread surveillance on communications, flew into Moscow from Hong Kong as he seeks asylum, possibly in Ecuador.

Russia has refused to hand Snowden over.

Moscow also is a key supporter of embattled Syrian President Bashar al-Assad, while Kerry has been working with Gulf Arab states to step up assistance to the opposition.

Kerry also is expected to meet Monday with European Union foreign policy chief Catherine Ashton following a report by German weekly Der Spiegel that Washington targeted EU offices in the spying programme revealed by Snowden.

En route to the small petro-sultanate of Brunei, this year's host of the annual diplomatic scrum, Kerry spoke again to Israeli Prime Minister Benjamin Netanyahu on reviving peace talks, a US official said.

Kerry had delayed his departure for the Asian meetings by a day as he shuttled between Netanyahu and Palestinian president Mahmud Abbas, hoping to restart talks after a nearly three-year hiatus.

Away from Kerry's sideline encounters, the official meetings in Brunei are likely to revolve in large part around regional concerns over China's rise.

During kick-off talks on Sunday among the 10-member Association of Southeast Asian Nations (ASEAN), the Philippines accused China of a "massive" military buildup in the disputed South China Sea, which it said threatened peace.

China, which claims virtually all of the strategic waterway, has been at odds with rival claimants, particularly the Philippines and Vietnam, leading to tense confrontations at sea and allegations of Chinese bullying.

"The Philippines views with serious concern the militarisation of the South China Sea," Foreign Secretary Albert Del Rosario told his ASEAN counterparts.

"The overwhelming presence of Chinese ships, including military and paramilitary ships, and the issuance of threats pose serious challenges for the region as a whole."

Temperatures have also risen in the East China Sea amid rival claims by Beijing and Tokyo to remote, uninhabited islands.

North Korea's nuclear programme has been one of the top global security concerns this year after Pyongyang carried out its third underground atomic test in February, while launching a series of dire warnings of war.

All foreign ministers from the long-running but currently stalled six-nation talks aimed at convincing North Korea to give up its nuclear weapons programme are in Brunei.

North Korea was expected to be a top focus for Kerry in talks with his counterparts from Japan, South Korea, China and Russia -- other members of the six-nation diplomatic effort.

But a direct meeting between Kerry and North Korean Foreign Minister Pak Ui-Chun was not expected.

Kerry was scheduled on Monday to meet with his Japanese and South Korean counterparts , as well as with Chinese Foreign Minister Wang Yi.

The Snowden affair has also put stress on US relations with Beijing, which Washington accuses of letting the American slip out of Hong Kong en route to Moscow.

And Japanese Foreign Minister Fumio Kishida was set to hold direct talks with South Korea's Yun Byung-Se on Monday for the first time since each country voted in new governments.

The ASEAN Regional Forum will wrap up the Brunei talks on Tuesday, gathering foreign ministers from 26 countries and the European Union.