The Obama administration slapped fresh sanctions on Syria’s biggest bank on Wednesday, a move that could harm the country’s ability to export oil, analysts and officials said.

The new penalty on the Commercial Bank of Syria, a state-owned institution, was the latest step in the administration’s efforts to tighten the noose around President Bashar al-Assad. The U.S. government, with little economic leverage of its own in Syria, has been trying to build a stronger international front to pressure Assad over his crackdown on pro-democracy demonstrators.

At least 2,000 peaceful protesters have been slain by Syrian forces since the uprising began earlier this year, according to U.S. officials.

White House spokesman Jay Carney reiterated Wednesday that Syria “would be better off without President Assad.” But he stopped short of an outright call on Assad to step down.

The George W. Bush administration had already banned U.S. companies from doing business with the Commercial Bank of Syria. But Andrew Tabler, a Syria expert at the Washington Institute for Near East Policy, said that those 2004 sanctions were weaker because they were an attempt to target money laundering. Therefore, they did not stop some European countries from doing business with the bank.

In contrast, the latest U.S. designation accuses the bank of providing financial services to Syrian and North Korean institutions allegedly involved in the proliferation of weapons of mass destruction.

“This will encourage the Europeans to target the Commercial Bank of Syria completely,” said Tabler, author of an upcoming book on U.S.-Syria relations, “In the Lion’s Den.”

Such a move would be significant because the bank handles Syria’s oil revenues, a major revenue source for Assad’s government. European countries are the biggest customers for Syria’s oil.

The latest sanctions also target Syriatel, the country’s largest mobile phone operator.

Syriatel is owned by Rami Makhluf, an influential Syrian businessman who was hit with U.S. sanctions earlier this month because of his support of the Assad government.

The U.S. government has been trying to increase pressure through sanctions on influential business allies of the Assad government, in hopes they will lessen their support.

David S. Cohen, the Treasury undersecretary for financial intelligence, said in a statement that the measures showed “we are taking aim at the financial infrastructure that is helping provide support to Asad and his regime’s illicit activities.”