A group of Republican senators have warned the European countries not to try to flout the sanctions that the US president is going to re-impose on Iran after pulling Washington out of the Iran nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA).

The 10 senators, all of whom opposed the JCPOA, said in a letter on Thursday to the ambassadors of Britain, France and Germany that they would be “particularly troubled” by any efforts to evade or undermine the sanctions.

The senators said the attempts to flout the American sanctions could be met by congressional action, according to AP.

A first set of US sanctions lifted by the Obama administration under the terms of the JCPOA is to be restored on August 4. The second set will be re-imposed on November 4.

The senators, including outspoken Iran deal critics Ted Cruz of Texas, Marco Rubio of Florida and Tom Cotton of Arkansas, noted that the sanctions are matters of US law and had been eased only because the previous administration had approved of the deal, which Trump pulled out of in May.

“We write to urge you to comply with all American sanctions but also to emphasize we would find it particularly troubling if you sought to evade or undermine American statutes,” the senators wrote. “These laws were passed by Congress, signed by President Obama and will be enforced by President Trump.”

“Any attempt to evade or subvert them could well prompt congressional action, in coordination with other elements of the US government, to ensure their integrity,” they said.

On May 8, the US president pulled his country out of the JCPOA, which was achieved in Vienna in 2015 after years of negotiations among Iran and the Group 5+1 (Russia, China, the US, Britain, France and Germany).

Under the JCPOA, Iran undertook to put limits on its nuclear program in exchange for the removal of nuclear-related sanctions imposed against Tehran.

Since the US president pulled Washington out of the nuclear deal, European countries have been scrambling to ensure that Iran gets enough economic benefits to persuade it to stay in the deal. The remaining parties have vowed to stay in the accord.

Following the US exit, Iran and the remaining parties launched talks to save the accord.

Meanwhile, Leader of the Islamic Revolution Ayatollah Seyed Ali Khamenei has underlined that any decision to keep the JCPOA running without the US should be conditional on “practical guarantees” from the Europeans.