After months of little progress in U.S.-China relations, President Joe Biden’s frustration led him to initiate a call with Xi Jinping in search of a breakthrough. Now the question is who will be first to take concrete action.

The leaders of the world’s biggest economies spoke by telephone for 90 minutes on Thursday night, their first discussion since February. While the call didn’t produce any immediate announcements, the yuan strengthened to a one-week high amid optimism that any communication could improve overall ties.

Still, the readouts after the conversation showed that fundamental differences remain. The White House sought to make a distinction between issues where the countries can cooperate and others where they will compete, while Xi linked everything to "respecting each other’s core concerns.”