The Stop Harboring Iranian Petroleum (SHIP) bill, which passed 342-69, would impose measures on foreign ports and refineries that process petroleum exported from Iran in violation of U.S. sanctions.

U.S. lawmakers are debating several pieces of legislation to pressure Iran after the Oct. 7 attacks on Israel by Hamas that killed at least 1,400 people, mostly civilians. Hamas has long been backed by Iran, but Tehran has denied any involvement in the attacks.

The bill "sends a clear and strong message to bad actors like China, Russia, and others – do not help Iran avoid sanctions and assist them in their funding of terror, or face the consequences," Representatives Mike Lawler, a Republican, and Jared Moskowitz, a Democrat, said in a release.

The bill must be passed by the Senate and signed by President Joe Biden before becoming law. A companion bill in the Senate is sponsored by Republican Senators Marco Rubio and John Kennedy and by Democratic Senators Maggie Hassan and Jacky Rosen.

It is unclear how effective the legislation would be if signed into law. While Congress can pass sanctions legislation, such measures often come with national security waivers that allow presidents discretion in applying the law. And China could continue to import the oil despite new sanctions.

Despite U.S. sanctions on Iranian oil over its nuclear program, its exports of crude are soaring. Iran says its nuclear program is for peaceful purposes.

Iran's crude exports of about 1.5 million barrels per day (bpd) stood at their highest in more than four years, with more than 80% shipped to China, data from consultancies FGE and Vortexa showed in September.