STORY: The US and China are demanding tit-for-tat additional port fees from ocean carriers amid the latest escalation of their trade war.These charges will affect ships carrying everything from toys to crude oil.China has already begun collecting fees from US-owned, operated, built or flagged ships.However, Chinese-made ships are exempt.Exemptions also apply to empty ships entering Chinese shipyards for repairs, according to state media.Meanwhile, the US will begin collecting wages on Tuesday. Earlier this year, the Trump administration laid out a plan to target China-linked ships in an effort to weaken Beijing’s dominance of global shipping and promote American shipbuilding.A previous investigation under former President Joe Biden found that China used unfair practices to control the shipping, logistics and shipbuilding industries, paving the way for new penalties.Chinese state-owned shipping giant COSCO could be hit the hardest, with the potential to account for nearly half of the estimated $3.2 billion in wages by 2026, one analyst said.Despite the turmoil, COSCO shares rose around 3% in early trading Tuesday.The company announced a plan to buy back shares worth approximately $210 million to preserve its value and reassure investors.COSCO did not immediately respond to a Reuters question about the potential impact of port fees.