Biden defiant on China, N Korea

Vice President Joe Biden's Asia tour was yet again overshadowed by regional tensions on Wednesday, this time during a visit to the South Korean capital, Seoul.

In talks with South Korean President Park Geun-Hye and later in a speech at Seoul's Yonsei University, Biden said the United States had warned North Korean leader Kim Jong Un that Pyongyang would never achieve prosperity as long as it continued to pursue nuclear arms

"The United States and the world have to make it absolutely clear to Kim Jong Un that the international community will not accept or tolerate nuclear arms in North Korea," Biden said.

"The simple fact is this - North Korea can never achieve security and prosperity so long as it pursues nuclear weapons, period," Biden said.

He added that the US was prepared to reengage with the so-called six-party nuclear talks, which North Korea called off in 2008, overturning commitments made under a 2005 disarmament deal.

"We are prepared to go back to the six-party talks when North Korea demonstrates its full commitment to a complete, verifiable and irreversible denuclearization," Biden said.

Tensions between North and South Korea where exacerbated in February this year, when Pyongyang conducted a third nuclear test, prompting the west to impose additional economic sanctions.

US 'does not recognize' zone

A separate regional dispute - triggered by China's creation of an air defense identification zone (ADIZ) over contested islands in the East China Sea - also dominated Biden's South Korea visit.

The vice president reiterated US opposition to the declaration of the zone - which has fueled tensions between Beijing and Japan - who both lay claim to the islands. The zone also crosses territory claimed by Seoul, which has threatened to expand its own air defense zone in retaliation.

Biden said he has stressed to China's President Xi Jinping during a visit to Beijing earlier this week, that the US military would not recognize its demand that it receive prior warning if planes plan to enter the zone.

"I was absolutely clear on behalf of my president: We do not recognize the zone. It will have no effect on American operations. None. Zero," Biden said.

Meanwhile Park said Biden's trip to the region would be "of much help for peace" in Northeast Asia.

"We are at a point in time when the situation in Northeast Asia is very fluid and tensions in the region are escalating," she said.

Biden has largely found himself playing mediator during his three-leg Asia tour, which as taken him to Japan as well as China and South Korea.

US pivot towards Asia

The Obama administration has sought to use Biden's trip to realign America's foreign-policy focus toward Asia in recognition of China's growing military power.

During talks with the South Korean president Biden stressed President Barack Obama's new security strategy, that emphasizes a shift, or "pivot", towards the Asia region, had not altered.

"I want to make one thing absolutely clear: President Obama's decision to rebalance to the Pacific basin is not in question," Biden said as the two leaders sat down for talks.

"The United States never says anything it does not do. It's never been a good bet to bet against America... and America will continue to place its bet on South Korea," he added.

Biden is expected to conclude his trip on Saturday with a visit the Demilitarized Zone between South and North Korea.

ccp/hc (AP, AFP, Reuters)