When Congress sent President Donald Trump a bill in July that slapped new sanctions on Russia, the president signed the legislation reluctantly while lambasting it as an example of congressional overreach.

The administration has since blown past an October 1 deadline to implement the sanctions. Lawmakers are now searching for answers as to whether the president is even planning to follow the law that they passed and he signed.

“If they don’t cooperate, then further actions need to be taken,” Sen. John McCain (R-AZ) told The Daily Beast on Monday. The Arizona senator, who chairs the powerful Armed Services Committee and has spoken out against the White House on its attitude toward Moscow, said the administration has left him in the dark.

But aside from procedural tactics, Congress is essentially powerless in compelling the executive branch to follow through on the law it forced them to sign.

The legislation, which was approved overwhelmingly by both houses of Congress, slapped sanctions on Russia and codified existing ones over its election meddling and incursions into eastern Europe that have drawn condemnation from the U.S. and its allies.

As The Daily Beast first reported, the Trump administration was engaged in active efforts to weaken a core part of the sanctions bill: that Congress would have the authority to review any attempts by the executive branch to unilaterally roll back or ramp up the sanctions. Despite those reservations and the attempts to water down the bill, support for the measure was veto-proof, and Trump signed the bill into law on August 2.

Per the legislation, the administration was required to issue guidance by October 1 on how it was implementing the sanctions against Russia. That process includes publishing a list of the people and organizations who will be targeted by the sanctions, which are primarily aimed at Russia’s defense and intelligence sectors.

But that deadline came and went without any actual guidance issued, and lawmakers feel as though they are being stonewalled by an administration which has the tools it needs to implement and enforce the sanctions, yet has not followed through. A National Security Council spokesman declined to comment to The Daily Beast.

“With all the tough talk coming from the White House, it’s baffling that the administration still hasn’t enforced any of the new sanctions Congress passed in August,” Rep. Eliot Engel (D-N.Y.), the ranking member on the House Foreign Affairs Committee, told The Daily Beast.

Lawmakers who serve on that committee have questioned the administration on the issue—but to no avail, according to a committee aide. The administration has thus far only named the federal departments and agencies working on the issue: the State Department, Treasury Department, and the Office of the Director of National Intelligence.

McCain and Sen. Ben Cardin (D-MD) sensed that the administration might try to delay the implementation of the sanctions, and preemptively wrote Trump in an attempt to ensure that he would implement the law. Nearly two weeks after the deadline passed, the senators issued a joint statement calling “into question the Trump administration’s commitment to the sanctions bill.”

A Cardin aide told The Daily Beast that the senator met with Tillerson on October 11 and that the secretary of state assured him the administration was taking the issue seriously. But 12 days later, the Maryland senator—who serves as the ranking member of the Foreign Relations Committee—and his colleagues are still in the dark.

“We should’ve heard by now. So we are disappointed. We have not gotten any follow-up from the letter and from the conversation I had with Secretary Tillerson,” Cardin told The Daily Beast. “There are opportunities that we plan to take advantage of. We have hearings, we have appropriations bills—there are a lot of things we can express ourselves on. And we’ll use every opportunity we can.”

The administration’s delay in implementing the sanctions comes as Congress and special counsel Robert Mueller are both investigating Russia’s election meddling. Trump has dismissed the probes as a “hoax” and “fake news.” But lawmakers have, nevertheless, expressed an urgency to punish Russia for its actions, warning that the Kremlin is poised to wage similar influence campaigns aimed at sowing division and chaos in the run-up to U.S. elections. That Trump doesn’t share that urgency continues to perplex even his Capitol Hill allies.

“The Trump administration is slow when it comes to Russia. They have a blind spot on Russia I still can’t figure out,” Sen. Lindsey Graham (R-S.C.) said Sunday on NBC’s Meet the Press. When asked what Congress could do to force the administration to act, Graham was vague, saying only: “The Congress will have a way to hold the president accountable.”

Lawmakers know their options are limited. But McCain went a step further than Graham. When asked by The Daily Beast if he would hold up the administration’s nominees until they act on the sanctions legislation, McCain replied: “Nominees are already being blocked.” He was referring to his threat last week to block Trump’s nominees to key defense and national security positions over what many lawmakers have characterized as an insufficient response to the ambush in Niger that resulted in the deaths of four American troops.