US president arrives for summit amid extraordinary security

U.S. President Barack Obama arrived in Malaysia on Friday on the final leg of a series of summits aimed at furthering Washington's bid to rebalance ties towards Asia and challenge China's increasingly assertive posture in the region.

Security was unusually tight in the Malaysian capital with police citing unconfirmed reports of an "imminent terrorist threat", following last week's attacks in Paris and the downing of a Russian airliner over Egypt by Islamic State militants.

Obama is joining leaders of the 10-member Association of South East Asian Nations (ASEAN) for a weekend summit. Leaders from seven other countries with close partnerships with the grouping - Australia, China, India, Japan, New Zealand, Russia and South Korea - will also attend a series of meetings starting on Saturday.

At least 2,000 army personnel were stationed at strategic points in Kuala Lumpur and another 2,500 were on standby, Armed Forces chief Zulkifeli Mohd Zin said.

Obama and most of the other leaders are arriving from the Asia Pacific Economic Cooperation (APEC) summit in Manila, where the U.S. President tried to turn the heat on China over its territorial claims in the disputed South China Sea.

Both the APEC meeting and the ASEAN summit typically focus on economic issues but have been overshadowed by global efforts to combat Islamic State following the attacks in Paris that killed at least 129 people.

NINE-DASH LINE

Beijing's claim to almost the entire South China Sea is shown on Chinese maps with a nine-dash line that stretches deep into the maritime heart of Southeast Asia. This clashes with claims by Taiwan and ASEAN members Vietnam, the Philippines, Malaysia and Brunei on atolls and islets scattered around strategic sealanes that annually carry $5 trillion worth of trade.

In talks with Philippine President Benigno Aquino on Thursday, Obama demanded China halt land reclamation work that is turning seven reefs in the Spratly archipelago into artificial islands. China is building airfields and other facilities on some of them. Earlier this month, U.S. B-52 bombers flew near the islands, signalling Washington's determination to challenge Beijing over the disputed sea.

While ASEAN has yet to take a collective stand about China's activities in the South China Sea, its secretary general said it was no surprise member countries are looking for peaceful ways to challenge it.

"They have the right to take any path or any process, as long as its a peaceful one conducive to a solution of the dispute," ASEAN Secretary General Le Luong Minh said in an interview.

In a legal setback for Beijing, an arbitration court in the Netherlands has ruled it has jurisdiction to hear some territorial claims the Philippines has filed against China over disputed areas in the South China Sea.

China said it does not want the South China Sea issue to be the focus of the meetings in Kuala Lumpur and a draft of the Chairman's statement to be issued at the end makes no mention of the recent tensions. It is still being negotiated, however.

U.S. REBALANCING ACT

Obama's has tried to emphasise the U.S. "rebalance" towards the Asia-Pacific with his signature Trans-Pacific Partnership trade deal and strengthening ties with Asian nations facing a more muscular China. But he has been dogged during his swing through the region by concerns over how to counter Islamic State militants blamed for the Paris attacks.

Much of his time at the G20 summit in Turkey and the APEC gathering in Manila was focused half a world away on the chaos and violence emanating from Syria's 4-1/2-year-old civil war.

He also has issues with Malaysia. Obama will "very directly" raise concerns about the status of Malaysia's political opposition during a bilateral meeting with Malaysian Prime Minister Najib Tun Razak, U.S. Deputy National Security Adviser Ben Rhodes told reporters on Thursday at the Asia-Pacific Economic Cooperation (APEC) summit in Manila.

Critics have accused Najib of escalating a crackdown on dissent and free expression after losing the popular vote in the 2013 general election. The prime minister has come under pressure himself after it was revealed in July that nearly $700 million in unexplained deposits were placed into his personal bank accounts. He has denied any wrongdoing but has yet to detail the source and purpose of the money he received.