The Obama administration is still weighing whether to apply "mandatory sanctions" called for in multiple laws on the sale of the S-300 air-defense missile system from Russia to Iran.

Officials have "objected" to the sale, but have refused to say for months whether they will levy sanctions as a result of it. Days after Iran deployed the S-300 around its Fordow nuclear facility, officials told THE WEEKLY STANDARD that the administration still has not made a decision.

"We have not yet made any determination as to whether this action would trigger any actions under U.S. authorities," a State Department official told TWS Wednesday. "As we continue to gather additional information we will consult with our partners."

The State Department provided a virtually identical response to a similar inquiry three months ago.

At least two laws—the Iran Sanctions Act and Iran-Iraq Arms Non-Proliferation Act—call for the president, in his discretion, to levy "mandatory sanctions" on foreign countries that help Iran acquire "destabilizing numbers and types of advanced conventional weapons.

The State Department official did not say whether the administration considered the S-300 to be an "advanced conventional weapon."

In the days following Iran's deployment to Fordow, the White House called the S-300 system "objectionable," but explained that it is "defensive" in nature and therefore is not in violation of any United Nations Security Council resolutions.

Officials have not said whether the sale will trigger sanctions under the aforementioned U.S. laws, which are separate from the U.N. resolutions.

The administration's silence on sanctioning the sale has sparked a fresh round of criticism from lawmakers.

"The Administration is failing to enforce U.S. laws that mandate sanctions against countries that export destabilizing advanced conventional weapons to Iran," Illinois senator Mark Kirk said in a statement Monday. "By allowing Iran to get destabilizing advanced S-300 missiles at Fordow, the Administration is making it harder to stop Iran from eventually getting nuclear weapons, especially because the flawed nuclear deal's temporary limits on Fordow's uranium enrichment capabilities completely expire in 15 years. That is, if we assume Iran does not cheat on the agreement first."

Reports have noted that the S-300 would make a future air strike on Iran's nuclear facilities, in the case that the Islamic Republic is not fulfilling its nuclear deal obligations, "nearly impossible."

"In a post–Iran nuclear deal scenario, the presence of the S-300 would make it far more difficult to strike Iran's nuclear facilities," according to a recent reportfrom the American Enterprise Institute. "The result of these developments will be a dramatic increase in Iran's ability to defend its airspace against all attackers, including the United States."

Russia renewed the S-300 sale with Iran last April after cancelling a similar arrangement in 2010.