Chat on website. Told (1st) agent (Aslam) I have EP on AA and 1K on UA. He was nonresponsive for several minutes and eventually said they can match. However, he immediately disconnected right after. The 2nd agent (Sofia) read through the chat history and said, "I have read the above query regarding tier status match, thank you for considering Cathay to match your membership status from our partner airline under One World Alliance. Kindly note that the Tier Matching request is currently closed until further notice. Thank you for your understanding!"