TOKYO (AP) — U.S. officials are claiming a breakthrough with Japan on a stalled regional trade pact, even though gaps remain.

U.S. and Japanese officials have emerged after two days of around-the-clock negotiations on the Trans-Pacific Partnership during President Barack Obama’s visit to Tokyo. The 12-nation pact is a key component of Obama’s effort to assert U.S. influence in Asia in the face of China’s ascendancy.

U.S. officials say the two sides have narrowed differences on market access issues related to agriculture and automobiles, two key sectors that have deadlocked negotiations.

The Japanese side is less upbeat, citing progress but no basic agreement.

Even if the two countries can resolve their differences, there are real doubts about whether Obama can rally political support for the agreement in Washington amid opposition from labor groups.