Iranian army members march during Army Day parade at a military base in northern Tehran, Iran on Wednesday. In the parade, President Ebrahim Raisi warned that the “tiniest invasion” by Israel would bring a “massive and harsh” response, as the region braces for potential Israeli retaliation after Iran’s attack over the weekend. Vahid Salemi/Associated Press

WASHINGTON – The U.S. and U.K. on Thursday imposed a new round of sanctions on Iran as concern grows that Tehran’s unprecedented attack on Israel could fuel a wider war in the Middle East.

The sanctions are meant to hold Iran accountable for its weekend attack and to deter further such activity. But the practical impact is likely to be limited because many of the targeted companies already were subject to U.S. sanctions and the individuals singled out for new sanctions are unlikely to have assets in U.S. jurisdictions.

Treasury’s Office of Foreign Assets Control targeted 16 people and two entities in Iran that produce engines that power the drones used in the April 13 attack on Israel. OFAC also sanctioned five firms involved in steel production and three subsidiaries of Iranian automaker Bahman Group – which is accused of materially supporting Iran’s military and other sanctioned groups. A representative from Bahman was not immediately available for comment.

Additionally, the U.K. targeted several Iranian military branches and individuals involved in Iran’s drone and ballistic missile industries.

President Biden said in a statement that he had directed U.S. Treasury “to continue to impose sanctions that further degrade Iran’s military industries.” “Let it be clear to all those who enable or support Iran’s attacks,” he said, “we will not hesitate to take all necessary action to hold you accountable.”

U.K. Prime Minister Rishi Sunak said in a statement that the sanctions “will further limit Iran’s ability to destabilize the region.”

In addition, the U.S. Commerce Department is imposing new controls to restrict Iran’s access to commercial-grade microelectronics, which applies to items manufactured outside the U.S. that are produced using U.S. technology.

The actions come after U.S. officials earlier this week warned that they were readying new sanctions in response to Iran’s activity in the region and to prevent future attacks. Lawmakers on Capitol Hill also have been quickly pushing forward legislation that would financially punish the Islamic Republic and its leaders.

Deputy State Department spokesman Vedant Patel told reporters Thursday that the U.S. reimposed travel restrictions on the Iranian delegation at the United Nations that prevents them from traveling outside a two-block radius of U.N. headquarters. These restrictions were imposed during the Trump administration but were lifted very early on by the Biden administration.

Iran’s attack on Israel early Sunday came in response to what it says was an Israeli strike on Iran’s consulate in Syria earlier this month. Israel’s military chief said Monday that his country will respond to the Iranian attack, while world leaders caution against retaliation, trying to avoid a spiral of violence.

European Union leaders also vowed on Wednesday to ramp up sanctions on Iran, targeting its drone and missile deliveries to proxies in Gaza, Yemen and Lebanon.

EU foreign policy chief Josep Borrell said the existing EU sanctions regime would be strengthened and expanded to punish Tehran and help prevent future attacks on Israel. At the same time, he said, Israel needed to exercise restraint.

“I don’t want to exaggerate, but we are on the edge of a war, a regional war in the Middle East, which will be sending shockwaves to the rest of the world, and in particular to Europe,” he warned. “So stop it.”

The U.S. has already sanctioned hundreds of entities and people in Iran – from the central bank and government officials to drone producers and money exchangers – accused of materially supporting Iran’s Revolutionary Guard and foreign militant groups such as Hamas, Hezbollah and the Houthis.

And U.S. efforts to limit Iran’s income from oil and petroleum products span back decades.

The question remains how effective sanctions will be, and have been, in preventing Iran from ramping up its production of military equipment. American defense officials accuse Iran of supplying drones to Russia as it pursues its invasion of Ukraine, which has reached a third year.

Richard Goldberg, who served as the director for countering Iranian weapons of mass destruction at the National Security Council during the Trump administration, called the new sanctions “important but unimpactful.”

Goldberg, who is a senior adviser at the Washington think tank Foundation for Defense of Democracies, said the sanctions rightly impose restrictions on entities involved in Iran’s manufacture of missiles and drones and reinforce some actions affecting key industries already on the books. But he said the new sanctions do not move the ball in forcing the Iranians to seriously change their calculus.

Daniel Pickard, a sanctions attorney at Buchanan, Ingersoll & Rooney in Washington, said “Iran is now and has been for years the biggest funder of terrorism and sanctions aren’t going to stop that – its the idea that the country is being essentially divorced from the international financial system” he said.

Citing the possibility of sanctions stifling Iran’s economy – “it could only take one more push for its economy to go into an unstoppable slide.”

Earlier this week, Treasury Secretary Janet Yellen said during a press conference that the U.S. has “been working to diminish Iran’s ability to export oil.”

”There may be more that we could do,” she said.

Associated Press reporters Aamer Madhani and Matt Lee contributed to this report.