Recent U.S. visa problems involving two lawmakers from the ruling Democratic Party of Korea (DPK) have drawn criticism over how Washington treats representatives of a key ally. The issue comes as relations between Seoul and Washington hit "turbulence," as described by U.S. Ambassador to Korea Michelle Steel, following a series of differing opinions over matters including the timeline of wartime operational control (OPCON) transfer, joint military exercises, the projects making up Korea's $350 billion investment commitment, intelligence sharing and Korea's regulations on American firms such as Coupang. Rep. Jin Sung-joon of the DPK, chair of the National Assembly’s National Defense Committee, said he received a visa refusal notice ahead of a planned visit to the country from Sunday to Thursday. The delegation, Jin and lawmakers from other parties, was due to visit the U.S. Indo-Pacific Command in Hawaii and meet its commander, Adm. Samuel Paparo. In a Facebook post Wednesday, Jin called the decision an affront to the Assembly. “It disregards the standing of Korea’s National Assembly