In a flurry of diplomacy on the first day of his two-day visit to Singapore, President Barack Obama's number two urged parties to reject bellicose threats in the South China Sea and East China Sea and "quickly" agree on rules to prevent conflict.

China claims nearly all of the strategically vital South China Sea, even waters close to the shores of its smaller neighbours, a regular flashpoint with smaller nations like Vietnam and the Philippines.

Beijing is also locked in an increasingly fractious maritime row with Japan in the East China Sea over a series of disputed islands -- a source of growing concern for Washington which has a defence alliance with Tokyo.

As well as meeting with Singaporean leaders, Biden took the opportunity to hold talks with Japanese Prime Minister Shinzo Abe, who was visiting Singapore on the same day as part of tour of Southeast Asia.

"We each expressed our concern about the rising tensions in the South China Sea," Biden told reporters after a meeting with Singapore Prime Minister Lee Hsien Loong.

"The United States urges all parties to reject coercion, intimidation and threats to the use of force," said Biden, who arrived late Thursday from an earlier visit to India.

"We encourage the ASEAN and China to quickly reach agreement on a code of conduct," he added.

Four members of the Association of Southeast Asian Nations -- Brunei, Malaysia, the Philippines and Vietnam -- are locked in rival claims with China and Taiwan over areas in the South China Sea.

The 10-nation grouping has been urging China to negotiate a legally binding code of conduct aimed at preventing conflict in the sea, but Beijing has said it prefers to deal with individual claimants.

Washington says it has an interest in the freedom of navigation in the sea, which hosts vital shipping lanes.

China in recent years has increasingly taken steps to enforce its claims, sparking the strongest protests from Philippines and Vietnam.

Biden in his remarks did not refer to any particular threats to the use of force or intimidation in the South China Sea.

But in June this year, a powerful arm of China's state-run media accused the Philippines of trying to provoke Beijing and warned it could lead to aggressive Chinese action.

"If the Philippines continues to provoke China... a counterstrike will be hard to avoid," said the commentary run by the People's Daily, the mouthpiece of the ruling Communist Party.

On his meeting with Abe, Biden said both leaders shared the view that the US-Japan alliance plays a central role in regional peace and stability.

"The vice president reaffirmed the US position on the East China Sea, including our alliance commitments," a US statement after the meeting said.

Biden also "highlighted the US view that all sides should take steps to reduce tensions", the statement added.

Biden said he also discussed trade ties, including a US-led initiative called the Trans-Pacific Partnership which aims to establish one of the world's biggest free trade zones.

"We're working hard with Singapore and others to get it done in 2013," Biden said.

Japan joined the talks for the first time this month with 11 other countries already holding negotiations -- Australia, Brunei, Canada, Chile, Malaysia, Mexico, New Zealand, Peru, Singapore, the United States and Vietnam.

Biden said the 12 countries account for 40 percent of world gross domestic product and would form the "core for a stronger global economic growth... in the 21st century".

Some analysts say the TPP is part of Washington's efforts to contain China, which is not a party to the ongoing negotiations.

China however is part of talks for a Regional Comprehensive Economic Partnership, a 16-nation free-trade bloc in Asia that excludes the US.

Before plunging into serious diplomacy Friday, Biden and his wife Jill were feted during a ceremony at the National Orchid Garden, where a new hybrid was named "Denrobium Joe and Jill Biden" in their honour.

"Never did I think in my wildest dreams that I would have an orchid named after me and my wife," Biden said.

"That was beyond any expectations I ever had as a child or as an adult."

On Saturday, Biden will visit a facility of US aerospace giant Pratt & Whitney and tour the US Navy's littoral combat ship USS Freedom.

The warship has been deployed to Singapore and the surrounding region for the next eight months to give teeth to Washington's strategic "pivot" towards Asia.

He will leave for Hawaii later on Saturday.