U.S. officials have not missed a deadline to impose new sanctions on Russian defense and intelligence industries, the State Department maintained Thursday.

“January 29 was the start date for this,” State Department spokeswoman Heather Nauert told reporters. “It was not a deadline to impose new sanctions on Russia.”

Some Democratic lawmakers have accused President Trump’s administration of ignoring the law after Monday came and went without new sanctions announcements against Russia. Nauert countered that U.S. experts are engaged in the “tedious” process of “comb[ing] through a heck of a lot of transactions” worldwide.

“It was the first day under which we had the authority under [federal law] to impose sanctions if we made the determination that some sanctionable activity had taken place,” Nauert said of the Monday start date. “There is currently no end date to that authority.”

Senate Democrats rejected that stance in a Tuesday message to Secretary of State Rex Tillerson.

“This is unacceptable,” Democratic Maryland Sen. Ben Cardin, the ranking member on the Foreign Relations Committee, wrote in a letter signed by 21 of his colleagues. “By imposing no new sanctions under CAATSA mandates, the U.S. remains vulnerable to an emboldened Russian government in advance of this November’s congressional election.” He was referencing the sanctions law that passed last year, the Countering America's Adversaries Through Sanctions Act.

Cardin had taken a milder tone on Monday, after the administration provided a staff briefing to lawmakers about their plans for the sanctions law. “I appreciate the administration’s engagement with Congress on this issue,” he said Monday evening. “The U.S. should be prepared to impose sanctions when the law is clearly violated. The administration should not rest in these efforts and I expect a frequent and regular dialogue on this issue.”

Nauert confirmed that new sanctions could be forthcoming. “The fact that we did not impose sanctions on the very first day that we had authority should, by no means, be interpreted as evidence that we will not impose sanctions in the future,” she said.