Seoul (AFP) – President Joe Biden has arrived in South Korea on his first Asia trip as US leader, aiming to cement economic and security ties with regional allies despite growing fears of a North Korean nuclear test. His first stop on Friday was a massive Samsung semiconductor factory, where he received a warm welcome from South Korea’s new President Yoon Suk-yeol, with global supply chain issues topping the agenda. 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 o…