WASHINGTON (Reuters) — The Trump administration is expected on Monday to announce new sanctions against individuals and entities involved in Iran’s nuclear, missile and conventional weapons programs to bolster its position that all UN sanctions against Tehran are now upheld, a move that key allies such as the Europeans are challenging.

Secretary of State Mike Pompeo is scheduled to hold a news conference at 11 a.m. EDT at the State Department along with National Security Advisor Robert O’Brien and several top cabinet members. Treasury Secretary Steven Mnuchin, Defence Secretary Mark Esper, Secretary of Commerce Wilbur Ross as well as U.S. Ambassador to United Nations Kelly Craft will be joining Pompeo at the news conference which the agency said will be about “on Iran Snapback Sanctions”.

U.S. claims to have triggered a snap back, or resumption, of virtually all U.N. sanctions against Iran, including the arms embargo, to come into effect at 8 PM on Saturday (00:00 GMT Sunday).

Other parties to the nuclear deal and most U.N. Security Council members have said they do not believe the United States has the right to re-impose the U.N. sanctions and that the U.S. move has no legal effect. On Friday, Britain, France and Germany told the Security Council that U.N. sanctions relief for Iran — agreed under the 2015 nuclear deal — would continue beyond Sunday, despite Washington’s assertion.