TOKYO (AP) -- Japan's top trade negotiator abruptly canceled a trip to Washington aimed at issuing a joint statement on a tariffs deal with the Trump administration, as a top government spokesman urged the U.S. side to speed up implementation of the agreement.

Trade envoy Ryosei Akazawa was scheduled to leave Tokyo for Washington on Thursday for a 10th round of talks, following up on the agreement announced on July 22.

But Chief Cabinet Secretary Yoshimasa Hayashi told reporters some details required further consultations, so the trip was postponed.

In July, the two sides agreed on a 15% tax on imports of most Japanese goods, effective Aug. 1, down from an earlier 25% rate announced by President Donald Trump as so-called "reciprocal tariffs" on the major U.S. ally. Japanese officials discovered days later that the preliminary deal would add a 15% tariff to other tariffs and objected. Officials in Washington have acknowledged the mistake and agreed to abide by the agreement on a 15% tariff, and to refund any excess import duties that were paid.

So far, that hasn't happened.

"We will strongly request the United States to amend its presidential order to correct the reciprocal tariffs and to issue the presidential order to lower tariffs on autos and auto parts," Hayashi said.

In an interview with Fox News earlier this week, U.S. Commerce Secretary Howard Lutnick said Washington was ready to finalize the deal, in which Japan also pledged to invest up to $550 billion in the United States in coming years.

Plans for Akazawa to visit Washington are undecided, Hayashi said during a daily briefing, with another nudge at the Trump administration.

"Japan and the United States have confirmed the importance of sincere and prompt implementation of the agreement between the two countries," he said, adding that a deal was essential for the economic security of both countries.