WASHINGTON  – The Trump administration expects economic sanctions that it is re-imposing on Iran this week to further cripple the Iranian economy and will aggressively enforce the measures, senior U.S. administration officials said on Monday.

The so-called snapback sanctions, due to come into force early on Tuesday, would target Iranian purchases of U.S. dollars, metals trading and other dealings, coal, industrial-related software and its auto sector.

Iran’s rial currency has lost half its value since April under the threat of revived U.S. sanctions. The plunge in the currency and soaring inflation have sparked sporadic demonstrations in Iran against profiteering and corruption, with many protesters chanting anti-government slogans.

President Donald Trump is aiming to cut off the Iranian leadership’s access to resources, the officials said. The United States also plans to re-introduce potentially more damaging sanctions on Iranian oil in November.

But the U.S. sanctions strategy has several weak spots, especially a reluctance by Europe and China to curtail business with Iran.

The European Union voiced regret on Monday at the looming U.S. sanctions.

Trump warned on Monday of “severe consequences” for people or entities that fail to wind down economic activities with Iran.

“The United States is fully committed to enforcing all of our sanctions, and we will work closely with nations conducting business with Iran to ensure complete compliance,” he said in a statement.

If Iran wants to avoid the reimposition of sanctions it should take up Trump’s offer to negotiate, White House national security adviser John Bolton said on Monday.

Asked on Fox News what Iran’s leaders could do, Bolton said: “They could take up the president’s offer to negotiate with them, to give up their ballistic missile and nuclear weapons programs fully and really verifiably not under the onerous terms of the Iran nuclear deal, which really are not satisfactory.”

“If Iran were really serious they’d come to the table. We’ll find out whether they are or not.”

The sanctions now being brought back were among those lifted under the 2015 deal between world powers and Tehran on curbing Iran’s nuclear program.

Foes for decades, the United States and Iran have been increasingly at odds over Iran’s growing political and military influence in the Middle East since Trump took office in January 2017.

Trump announced this May he would withdraw the United States from the Iran nuclear deal.

Iranian Foreign Minister Mohammad Javad Zarif said on Monday that Trump and U.S. allies Israel and Saudi Arabia have become isolated by their hostile policies toward Tehran, state TV reported.

“Their oppressive policies and violent measures have made them isolated … The world has distanced itself from their hostile policies against Iran,” Zarif was quoted as saying.

The sanctions aim to modify Iran’s behavior and not bring about a “regime change” targeting President Hassan Rouhani, the U.S. officials said. They said the Iranian government’s handling of social and labor protests was a concern.

EUROPE WORRIED

The European Union expressed concern at the new U.S. move.

“We deeply regret the re-imposition of sanctions by the U.S.,” the bloc said in a joint statement with the foreign ministers of France, Germany and Britain.

One EU measure to mitigate the impact of U.S. sanctions, known as the blocking statute, will come into force on Tuesday.

One U.S. official said the administration was deeply concerned about reports of Iran’s violence against unarmed citizens. “The United States supports the Iranian people’s right to peacefully protest against corruption and oppression without fear of reprisal,” the official added.

The U.S. officials added that Trump was ready to meet with Iran’s leaders at any time to try to forge a new agreement.

Trump “will meet with the Iranian leadership at any time to discuss a real comprehensive deal that will contain their regional ambitions, will end their malign behavior and deny them any path to a nuclear weapon,” one official said.

Asked about possible exemptions to the sanctions, officials said they would examine any requests on a case-by-case basis.