U.S. allies in Europe are lamenting President Donald Trump's move to abandon the multinational nuclear deal with Iran.

Trump criticized the agreement reached by the Obama administration as "defective at its core" and declared Tuesday that by pulling out he is making the world safer.

The agreement in 2015 lifted most U.S. and international economic sanctions against Iran. In exchange, Iran agreed to restrictions on its nuclear program, making it impossible to produce a bomb and establishing rigorous inspections.

Facing renewed sanctions from the U.S., Iran's leader ominously warned Tuesday that his country might "start enriching uranium more than before."

Officials of Germany, France and Britain tried but failed to persuade Trump to keep the U.S. in the deal. China and Russia are also parties to the agreement.