As Trump agreed to the sanctions relief, US Department of Treasury on Friday said that it has imposed new sanctions on 14 individuals and entities over Iran's alleged human rights abuses and ballistic missile programme, including head of Iran's judiciary and the cyber unit of the Islamic Revolution Guards Corps.
Although Trump approved the waiver on USA sanctions as spelled out in the deal, Washington announced other sanctions against 14 Iranian entities and individuals, including judiciary head Ayatollah Sadeq Larijani, a close ally of Iran's Supreme Leader Ayatollah Ali Khamenei.
Mr. Trump now will work with European partners on a follow-on agreement that enshrines certain triggers that the Iranian regime can not exceed related to ballistic missiles, said senior administration officials who briefed reporters on the decision.
The officials said Trump expected America's European allies who are also parties to the 2015 accord, which swapped sanctions relief for a rollback of Iran's nuclear program, to join with him in reworking the deal.
USA officials said the new sanctions were for human-rights abuses by the Iranian regime during its response to civil protests, and for weapons proliferation.
Two senior Trump administration officials told Reuters on Wednesday that the president, a Republican, had privately expressed reluctance to heed the advice of top advisers recommending he not reimpose the suspended sanctions.
Trump did, however, warn that Friday's waiver would be the last time he was prepared to prevent Congress from putting sanctions in place, unless a significantly strengthened agreement was reached with Iran and the United States' European allies within 120 days. With a looming deadline on Friday over waiving the sanctions, it's unclear what the President will do.
Senate Foreign Relations Committee Chairman Bob Corker has been working on amending a U.S. law to include "trigger points" that if crossed by Iran would automatically bring back United States sanctions. A White House spokesperson says that deal should address Tehran's ballistic missile program, tighten inspections, eliminate the agreement's sunset clauses and limit Iran to a one year breakout to obtain a nuclear weapon.
And the argument the Europeans make is you want to keep the spotlight on the Iranian administration, on the Iranian leadership. He is also demanding a permanent end to Iran's enrichment of fissile material at a grade sufficient for weapons use.
Iran has been abundantly clear that it will not renegotiate the deal.
The violent street protests that have spread throughout much of Iran in recent weeks seemed like effective pretext for Trump to reimpose sanctions, since he could argue that Iran's sclerotic regime was on its last legs, and that the US had even less reason than normal to prop it up.
Trump had certified the deal twice before, and senior officials have grudgingly said Iran is complying.