U.S. President Joe Biden will speak with Chinese leader Xi Jinping on Thursday amid fresh tensions over Taiwan, according to people familiar with the matter.

The first conversation between the two presidents since March will take place at a particularly difficult juncture for U.S.-China ties: U.S. House Speaker Nancy Pelosi’s staff and security officials aren’t ruling out plans for her to visit Taiwan in early August.

Chinese Foreign Ministry spokesman Zhao Lijian said Monday that Beijing was getting "seriously prepared” for the possibility that Pelosi could visit the the self-governing island, which China considers part of its territory.