Japanese media reported on July 3 that the country’s prime minister Shinzo Abe has cancelled his plan to visit Iran during this summer.

The visit would have been the first by a Japanese leader since the Islamic revolution in 1979. Abe planned to meet Iranian president Hassan Rouhani.

But government sources told the media that the prime minister has dropped his plans, in what appears to be mounting American pressure on allies to isolate Iran.

In late June, the U.S. began a harder push to dissuade its allies from buying Iranian oil. Japan was on the top of the list of the countries U.S. intends to persuade to buy oil from other sources.

The Japan Times reports that Tokyo has told the U.S. it cannot reduce Iranian oil imports any further, fearing an impact on its economy. Iran has been one of Japan’s key suppliers of oil for decades.

Washington is expected to put more pressure, as Secretary of State Mike Pompeo visits Japan this weekend.

It is reported that Abe will still visit Saudi Arabia and Egypt during an eleven-day trip that will also take him to Paris and Brussels.