The Trump administration Tuesday added 18 more entities and individuals to its Iran sanctions list, just a day after it certified to Congress that Tehran has continued to meet the required conditions of its nuclear deal with the United States and other world powers.

Senior administration officials had made clear that the certification was grudging and indicated that new sanctions would closely follow for Iran’s “malign activities” in nonnuclear areas, such as ballistic missile development and support for terrorism.

“We judge that these Iranian activities severely undermine the intent” of the agreement as a force for international stability, one official said. Iran is “unquestionably in default of the spirit of the JCPOA,” or Joint Comprehensive Plan of Action, which took effect in January 2016 after years of negotiations, the official said.

International monitors and other signatories of the agreement have said Iran is meeting its terms, giving the administration little room for maneuver in providing the assessment required by Congress every 90 days.

The last certification of Iranian compliance, in April, was also followed by new sanctions on Iranian individuals and companies that the administration said played a role in ballistic missile tests not covered by the nuclear agreement.

The latest sanctions include seven entities and five individuals the Treasury Department said engaged in “activities in support of Iran’s military or Iran’s Islamic Revolutionary Guard Corps.” The list also includes “an Iran-based transnational criminal organization and three associated persons.”

In addition to aiding Iran’s military procurement, the Treasury Department said the “networks” helped the Revolutionary Guard — a branch of the military that answers only to Iranian religious authorities — develop unmanned aerial vehicles and “fast attack boats.”

Five of the companies that allegedly supported Iranian military procurement are based in China and one in Turkey. In addition, an Iranian company, Ajily Software Procurement Group, was said to have “orchestrated the theft of U.S. and western software programs which, at times, were sold to the Government of Iran.” U.S. export controls prohibit Iran from buying the programs.

The Revolutionary Guard itself was designated for sanctions by the Treasury Department in 2007. The State Department on Tuesday separately designated two Guard organizations for engaging in prohibited proliferation activities.