WASHINGTON—Congressional Democrats are intensifying pressure on the Obama administration to hold Iran accountable for its testing of ballistic missiles.

Both supporters and opponents of the multinational nuclear accord with Iran say that to maintain U.S. credibility in enforcing the deal, the White House must move forward with sanctions on Iran after two missile tests in the fall.

The administration in late December told lawmakers it planned to impose new financial penalties on nearly a dozen companies and individuals for their alleged role in developing Iran’s ballistic missile program. It then reversed course, saying it needed more time for diplomatic work with the Iranian government, but it hasn’t given a timeline for when they would be imposed.

The delay has put some Democrats, particularly those who represent large Jewish constituencies and donors, in an uncomfortable position. Many such lawmakers agonized this summer over whether to support the nuclear deal, which was opposed by Israel, saying their backing was contingent on strict oversight of Iran’s behavior.

“They ought to impose sanctions because we have to show we take this seriously,” Rep. Jerrold Nadler (D., N.Y.), who backed the nuclear deal, said in a recent interview. “Iran is very destabilizing, very aggressive and very badly behaved and we have to do what we can to stop that.”

“We will issue those sanctions and those designations at the appropriate time. There’s no question about it,” Denis McDonough, the president’s chief of staff, said on Fox News Sunday.

By The Wall Street Journal