WASHINGTON (Reuters) - President Donald Trump on Wednesday ordered new sanctions on Iran, this time targeting the Islamic Republic’s export revenues from its industrial metals sector, and vowed to keep squeezing Tehran unless it “fundamentally alters” its policies.

The announcement was made on the anniversary of Trump’s unilateral withdrawal of the United States from a 2015 landmark deal between Tehran and world powers to curb its nuclear program in exchange for easing some sanctions and hours after Tehran said it would no longer fully comply with the accord.

Tensions were already high between Washington and Tehran when the Trump administration said last weekend that it was deploying a carrier strike group and bombers to the Middle East, in response to what it said were “troubling indications and warnings” from Iran.

Before Trump’s executive order for the sanctions, a senior White House official said Washington would impose more economic curbs on Tehran ‘very soon’ and had warned Europe to stop doing business with the Islamic Republic.

“Today’s action targets Iran’s revenue from the export of industrial metals - 10 percent of its export economy - and puts other nations on notice that allowing Iranian steel and other metals into your ports will no longer be tolerated,” Trump said in a statement.

“Tehran can expect further actions unless it fundamentally alters its conduct,” Trump said.

The Trump administration says the nuclear deal, negotiated by his predecessor Barack Obama, was flawed as it is not permanent, does not address Iran’s ballistic missile program and does not punish it for waging proxy wars in other Middle East countries.

Leading Democratic lawmakers such as Chris Murphy, the top Democrat on the Senate’s Middle East subcommittee, said Iran’s halting compliance to some parts of the deal was “disastrous news” and accused Republican Trump’s administration of making America much less safe through its policies. House of Representatives Speaker Nancy Pelosi requested a briefing on Iran for members.

Hours before the fresh U.S. sanctions, Iranian President Hassan Rouhani announced Tehran was reducing curbs to its nuclear program with steps that for now stopped short of violating the 2015 accord. But it threatened more action if countries did not shield it from sanctions.

Tehran halting compliance with some elements of the nuclear deal was “nothing less than nuclear blackmail of Europe,” Tim Morrison, special assistant to the U.S. president and senior director for weapons of mass destruction, told a conference.

“Now is the time for the community of nations to strongly condemn Iran’s nuclear misconduct and increase pressure on the regime to comply with U.S. demands,” Morrison said, adding that Washington was not ‘done’ with sanctions on Iran.

Morrison said the United States would move quickly against any attempt by European countries to undermine Washington’s sanctions pressure on Iran. He advised them against using the so-called Special Purpose Vehicle to facilitate non-dollar trade to circumvent U.S. sanctions.

“If you are a bank, an investor, an insurer or other business in Europe you should know that getting involved in the ... Special Purpose Vehicle is a very poor business decision,” Morrison said.

Spearheaded by national security adviser John Bolton, the Trump administration has taken several unprecedented steps to squeeze Iran such as demanding the world halt all Iranian oil imports and designating Iran’s elite Revolutionary Guard Corps as a foreign terrorist organization, which Iran has cast as an American provocation.

“We have made our focus diplomatic isolation and economic pressure and that policy is working,” Brian Hook, Special Envoy for Iran, said in a briefing. Hook said that more nations now, compared with a year ago, were in agreement with the United States on Iran.

Washington’s European allies opposed Trump’s decision to withdraw from the nuclear deal and have failed so far to find ways to blunt the economic impact of new U.S. sanctions.