The United States is obliged to defend the Senkaku islets in the East China Sea in line with the Japan-U.S. security treaty, U.S. President Barack Obama assured Prime Minister Shinzo Abe in Tokyo on Thursday, while urging Tokyo and Beijing to resolve their territorial dispute peacefully.

The two leaders, however, were unable to issue a joint statement after their summit because they could not reach a broad basic accord on the U.S.-led Trans-Pacific Partnership trade pact by the end of their talks.

Negotiators from the two countries continued bilateral discussions Thursday afternoon but failed to reach a comprehensive agreement.