Biden says US 'pivot' to Asia cannot be derailed

US Vice President Joe Biden said today there should be no doubt about US commitment to its strategic shift to Asia as he started the final leg of a regional tour dominated by security concerns.

Meeting with South Korean President Park Geun-Hye in Seoul, Biden said the 60-year military alliance between the two countries was as strong as ever, amid regional tensions over China's declaration of a new air defence identification zone and North Korea's nuclear weapons programme.

"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.

President Barack Obama last year unveiled a new security strategy that emphasised a shift or "pivot" towards the Asia region, reflecting worries over China's growing military power.

But he called off a trip to the region in October to negotiate with Republicans over a budget impasse that had triggered automatic cuts to US military spending, raising concerns in Asia that the promised rebalance could be derailed.

Seoul was Biden's last stop on a three-country Asia tour that has already taken him to China and Japan.

President Park was expected to press Biden todday morning on China's new "air defence identification zone" (ADIZ), which has not only inflamed Beijing's territorial disputes with Japan, but also overlaps South Korea's own ADIZ.

Seoul has threatened to announce the expansion of its ADIZ in retaliation -- a move Biden is expected to discourage as Washington seeks to calm what is already a dangerously volatile mood in the region.

During his stops in Tokyo and Beijing, Biden underlined Washington's opposition to Beijing's move, but stopped short of demanding that China rescind the air zone.

Tensions in the region are at their highest in years, with China and Japan squaring off over a chain of uninhabited islands in a feud that has some observers warning of the danger of an armed confrontation.

Seoul has also denounced the new Chinese air zone which covers a tiny, South Korean-controlled rock in the East China Sea that is also claimed by Beijing.

As well as seeking to reassure Park, Biden will be looking to encourage Seoul to pursue better relations with Tokyo.Since the end of the 1950-53 Korean War.