TOKYO (Reuters) -Japan's leading trade negotiator said on Tuesday that the trade deal Tokyo agreed with the United States last week guarantees Japan will always receive the lowest tariff rate on chips and pharmaceuticals of all the pacts negotiated by Washington.

"If a third country agrees with the United States on lower rates on chips and pharmaceuticals, those lower rates would apply to Japan," Ryosei Akazawa told a news conference.

The European Union secured a 15% baseline tariff as part of a framework trade deal with the U.S. this week, averting looming new tariffs on chips and pharmaceuticals.

Japan last week struck a trade deal with the U.S. that lowers tariffs on cars and other goods to 15% in exchange for a U.S.-bound $550 billion Japanese investment package including equity, loans and guarantees.

Asked why there has been no joint statement on the agreement, Akazawa said Japan is prioritising having President Donald Trump sign an executive order to bring the agreed 15% tariff rate into effect.

"We want to concentrate our efforts on getting the tariffs lowered first, and then we can consider whether an official document on the agreement is necessary," he said.