The leaders of China and Japan held an ice-breaking summit Monday after two years of dangerous animosity, as world leaders including Barack Obama gathered for an Asia-Pacific meeting spotlighting intensifying big-power rivalries.

Xi Jinping and Shinzo Abe met in Beijing's Great Hall of the People in what the Japanese prime minister said was a "first step" towards repairing the fractured relationship between the world's second- and third-largest economies.

US President Obama flew in still wounded by the Democrats' defeat in the US mid-term elections and with relations between Washington and Moscow in the deep freeze, while his Russian counterpart Vladimir Putin arrived a day earlier and quickly signalled his desire for ever-warmer ties with an increasingly assertive China.

The gathering is the biggest event yet hosted by the Chinese president, who took office last year and spotlighted his country's expanding world profile Sunday by declaring a bright future ahead for the vibrant Pacific Rim -- with a confident China at its heart.

The annual two-day summit of Asia-Pacific Economic Cooperation (APEC) typically sees pledges of amity and trade convergence, often balanced by tense sideline exchanges on festering geopolitical problems.

Beijing and Tokyo's historically frosty relations have plunged to their lowest in decades over competing claims to Japanese-controlled islets in the East China Sea.

Abe told Japanese media that he asked Xi to establish a hotline aimed at preventing clashes at sea, adding "I think we will start working on concrete steps toward it".

But a Japanese official said the islands were not specifically mentioned during the 30 minutes of talks, Japan's Kyodo news agency reported.

The meeting appeared strained, with footage of the two leaders' initial handshake showing them looking deadpan and Xi not responding to Abe's greetings.

"Severe difficulties have emerged in Sino-Japanese relations in recent two years and the rights and wrongs behind them are crystal clear," China's official news agency Xinhua quoted him as saying.

- Russia, China's 'fruitful' friendship -

APEC brings into focus the developing big-power rivalry involving Washington, Beijing and Moscow.

Russia is under Western economic sanctions over its seizure of Ukraine's Crimea region and role in that country's separatist war.

No Obama-Putin meeting is known to be scheduled, but Australian Prime Minister Tony Abbott has vowed to confront the Russian strongman over Malaysia Airlines flight MH17, which was brought down over eastern Ukraine in July, with 38 Australians among the 298 dead.

The West has accused pro-Russian rebels of blasting it out of the sky with a missile and Moscow of impeding investigations. Russia denies the accusations.

Russia and China both regularly express impatience with a perceived American domination of world affairs and often move in tandem on the UN Security Council, vetoing or abstaining from US-led initiatives.

Increasing use of their ruble and yuan currencies meant that "the influence of the dollar in the global energy sector will objectively decline", Putin told APEC delegates Monday. "This is not bad for the global economy, nor for the world of finance or for the energy markets."

He and Xi met Sunday in Beijing, with the Chinese leader warmly calling for the once-bitter Cold War rivals to continue to "harvest" the fruits of their friendship.

"No matter the changes on the global arena, we should stick to the chosen path to expand and strengthen our comprehensive mutually fruitful cooperation," Xi said.

- 'Candid' conversations -

China and the United States have already jousted in Beijing over differing visions of Asia-Pacific trade integration, adding to persistent discord over commerce, human rights, cyber-espionage, and territorial disputes.

The White House has said it expects "candid and in-depth conversations" between Obama and Xi.

As well as the row with Japan -- a US security ally Washington is bound by treaty to defend if attacked -- Beijing's growing assertiveness in the South China Sea has also rankled rival claimants to its strategic waters.

Another likely discussion topic between Xi and Obama is North Korea, following the surprise weekend release of two Americans who were imprisoned by the secretive state.

Beijing is Pyongyang's closest ally, and the prisoner release could fuel speculation on the mercurial North's motives for its latest move.

It should be all smiles, however, when the APEC leaders gather Monday for a "family photo", when they typically wear the host's national dress.

The event culminates Tuesday with a formal leaders' summit.

APEC kicks off a week of high-level summitry that will see Obama and other top leaders travel next to Myanmar for the East Asia Summit, followed by G20 talks in Brisbane, Australia.

China is hosting APEC for the first time since 2001, when it was still re-emerging as a world economic power.

But in a speech Sunday, Xi underlined how much has changed by offering his vision of an "Asia-Pacific dream", in which China's continued rise offers "infinite promise" to all.