TOKYO (Reuters) -Japan's top trade negotiator Ryosei Akazawa said it might take some time for U.S. tariffs on automobiles to be lowered to 15%, public broadcaster NHK reported on Thursday.

Under a bilateral trade deal clinched with Japan earlier this month, the U.S. agreed to lower "reciprocal" tariffs on goods and a levy on automobiles both to 15% from the current 25%.

Speaking to reporters after the government's task-force meeting on U.S. tariffs, Akazawa said he expects the U.S. to cut the "reciprocal" tariffs to 15% from Friday as agreed upon by the two countries, according to NHK.

But he said the cut to tariffs on Japanese automobiles "may take some time," adding that Tokyo would step up requests for President Donald Trump to sign an executive order at an early date, NHK said.

Japan's auto sector accounts for more than a quarter of its U.S. exports and is a key engine of the fragile economy.