Biden starts Asia trip in S Korea

US President Joe Biden arrived in South Korea yesterday, his first Asia trip as US leader, aiming to cement ties with regional security allies despite growing fears of a North Korean nuclear test.

Biden wants the trip to boost a years-long US pivot to Asia, where rising Chinese commercial and military power is undercutting Washington's dominance.

He received a warm welcome from South Korea's new President Yoon Suk-yeol, but there is growing concern that North Korea's unpredictable leadership could conduct a nuclear test while he is in the region.

Biden, in his first remarks since arriving in South Korea at the start of a trip meant to demonstrate US resolve to lead in Asia, said the two countries' alliance was "a lynchpin of peace, stability and prosperity" in the world.

Speaking at a huge Samsung semiconductor factory in Pyeongtaek, alongside Yoon, Biden described the advanced chips manufactured there as "a wonder of innovation" and crucial to the world's economy.

The tiny, smart wafers "enable our modern lives" and are "the key to propelling us into the next era of humanity's technological development", he added.

Semiconductors -- the microchips essential to most modern devices from phones to cars and high-tech weapons -- are at the heart of a global supply chain slowdown that threatens to disrupt the world's post-Covid economic recovery.

South Korea and the United States need to work to "keep our supply chains resilient, reliable and secure", Biden said.

South Korea is a semiconductor powerhouse, supplying about 70 percent of chips globally.

Security issues were not top of the agenda yesterday, but the fact that Biden is visiting Seoul first on his Asia tour indicates that Washington is looking to re-focus on the Korean Peninsula, Soo Kim, a former CIA analyst, told AFP.

Biden heads to Japan from South Korea tomorrow. He will hold talks with the leaders of both countries, as well as joining a regional summit of the Quad -- a grouping of Australia, India, Japan and the United States -- while in Tokyo.