Top U.S. diplomats are headed to Beijing this week to try and get derailed negotiations over U.N. Security Council sanctions against Iran back on track. President Barack Obama’s recent decisions to meet with the Dalai Lama and allow a new arms sale to Taiwan have jeopardized talks with Beijing on the issue, senior White House and State Department officials acknowledged.

The U.S. and China need “to get over their reaction to the Dalai Lama’s visit and the arms sale,” National Security Adviser General James Jones told TIME last week. If sanctions against Iran are to move forward at the U.N., “we have more work to do with China,” Jones said. “Hopefully we’ll get back on track.”