A U.S. push to change the Iran nuclear deal was sending a "very dangerous message" that countries should never negotiate with Washington, Iran's foreign minister warned as U.S. and North Korean leaders prepare to meet for denuclearization talks.

Speaking to reporters in New York on Saturday, Mohammad Javad Zarif also said that for French President Emmanuel Macron and German Chancellor Angela Merkel "to try to appease the president (Donald Trump) would be an exercise in futility."

Trump will decide by May 12 whether to restore U.S. economic sanctions on Tehran, which would be a severe blow to the 2015 pact between Iran and six major powers. He has pressured European allies to work with Washington to fix the deal.