President Donald Trump slapped more sanctions on Iran today, claiming they constitute the “highest sanctions ever imposed on a country.”

Trump had threatened the sanctions earlier this week after the United States accused Iran of launching the attack on two Saudi oil facilities on Saturday — charges Tehran denies. The sanctions target Iran’s central bank and its sovereign wealth fund for providing financial support to the Islamic Revolutionary Guard Corps’ Quds Force and its Lebanese proxy, Hezbollah.

Although Congress first slapped sanctions on Iran’s central bank in 2011, the additional designation under the Treasury Department’s counterterrorism authority could set up political roadblocks for the majority of Democratic presidential candidates who have vowed to lift sanctions and reenter the nuclear deal. Today’s sanctions could also severely undermine the last vestiges of humanitarian trade with Iran.

“Opponents [of the nuclear deal] are trying to box in a future president from lifting sanctions,” Tyler Cullis, a sanctions lawyer at Ferrari & Associates, told Al-Monitor. “They’re setting up to hit you hard if you do it. And there’s no way to get a better Iran policy and reenter the deal unless you can lift those sanctions.”