Japan and the United States failed to overcome persistent obstacles to the Trans-Pacific Partnership as their latest round of negotiations ended Wednesday without agreement.

Lack of progress by the two largest economies in the Trans-Pacific Partnership clouds a goal set by President Barack Obama of its 12 negotiating members reaching agreement by the time they meet for an unrelated summit in November.

"We were unable to make further progress on the key outstanding issues," said the Office of the U.S. Trade Representative, referring to the agriculture and auto sectors, after two days of talks between economy minister Akira Amari and U.S. Trade Representative Michael Froman in Washington.