Phnom Penh (AFP) – Southeast Asian regional bloc ASEAN gained a surprise new member from the other side of the world Saturday — at least for an instant, courtesy of a verbal slip by US President Joe Biden. “I want to thank the prime minister for Colombia’s leadership as ASEAN chair,” Biden said as he opened talks with regional leaders in Phnom Penh chaired by Cambodian Prime Minister Hun Sen. South America’s Colombia seems to be on the US president’s mind, because he made the same mistake as he set out from the White House for his long trip to Asia. He told reporters he was “heading over to C…