U.S. senators from the Republican Party have sent a letter to the embassies of Germany, France, and the United Kingdom in the United States with a warning against any possible moves to circumvent the Trump administration’s sanctions against Iran, the news portal t-online.de reported on Sunday.

“We write to urge you to comply with all American sanctions, but also to emphasize we would consider it particularly troubling if you sought to evade or undermine American statutes,” the letter, which was dated Thursday, says.

The U.S. lawmakers stressed that U.S. sanctions were not just a government decree, but that many of them originate from federal laws passed by Congress.

The senators also noted that sanctions were a considered and long-term U.S. policy, and attempts to circumvent them by European countries will prompt relevant U.S. actions.

In early May, President Donald Trump announced his decision to pull out of the Iran nuclear agreement signed in 2015 in Vienna between Iran, the European Union, China, France, Russia, the United Kingdom, the United States and Germany. The U.S. president also announced the restoration of all sanctions against Tehran, including secondary ones that apply to other countries conducting business with Iran.

Washington's European partners have repeatedly stated that they intended to continue to observe the terms of the deal with Iran.