WASHINGTON -- With less than a month before the deadline for a nuclear deal with Iran, Sens. Mark Kirk (R-Ill.) and Bob Menendez (D-N.J.) filed an amendment to the must-pass defense budget that would extend Congressional sanctions against Iran for 10 additional years.

If passed, the amendment would extend the Iran Sanctions Act of 1996, currently set to expire at the end of 2016, to the end of 2026. Because these sanctions target Iran�s intercontinental ballistic missiles program and support for terrorism -- not its nuclear program -- they would not be part of the sanctions terminated or suspended as part of a nuclear deal between Iran, the U.S. and its five negotiating partners.

The proposed sanctions extension threatens to complicate the already delicate negotiations currently taking place around Iran's nuclear program. Under those negotiations, the international community would provide sanctions relief to Iran in exchange for Iran dismantling parts of its nuclear program and limiting others. An agreement of principles has been reached, but the final language must be hammered out by the end of June. Congress has generally given the administration room to negotiate, with the understanding that they ultimately will have final say on the suspension of congressionally enacted sanctions. The latest Kirk-Menendez proposal could disrupt that arrangement by suggesting to the Iranians that the Obama administration cannot control his legislature�s sanctions policy.

For that reason, Peter Billerbeck, a former Senate staffer and current policy adviser at a think tank called Third Way, slammed the proposed amendment as �needlessly reckless and premature, especially at this point in the negotiations when we�re at the one-yard line.� He added, �We�re at the most critical stage of talks and it�s the last thing we need.�

In a statement echoing Billerbeck�s comments, the National Iranian American Council noted that Congress has ample time to pass an extension of the 1996 sanctions after the completion of the nuclear negotiations. �Taking action on this matter now, in the middle of negotiations, would be premature and counterproductive,� the group said.

In January, Kirk and Menendez introduced a bill that would impose additional sanctions on Iran if negotiators failed to reach a deal by their self-imposed June 30 deadline. President Barack Obama warned that passing the bill in the midst of ongoing nuclear negotiations could derail the entire process. He threatened to veto the legislation, and lobbied Democratic lawmakers to withhold their votes.

Despite widespread bipartisan support in the Senate for the sanctions bill, Kirk and Menendez agreed to hold off on their bill until after June, and instead backed a separate bill that cemented Congress� vote on the suspension of congressionally enacted sanctions in the event of a nuclear deal.

The alternate bill, which was signed into law last month, was hailed as a victory by both the Obama administration and Congress. The executive branch said it succeeded in removing controversial sections of the bill that would interfere with the nuclear negotiations. Lawmakers claimed they had secured much-needed oversight of the final agreement.

�As several of the bill�s supporters articulated, it ensures Congress will have its chance to weigh in on whether to support or oppose a nuclear deal and on the issue of sanctions, but only once the negotiations are completed,� NIAC said, referring to the new law. �The Kirk-Menendez amendment is one of several offered to the [defense authorization] regarding Iran that represent a breach of that bipartisan promise.�

Senate Armed Services Committee Chairman John McCain (R-Ariz.) and ranking member Jack Reed (D-R.I.) will ultimately decide which of the proposed amendments come up for a vote on the Senate floor. Obama has said he will veto the defense authorization in its current form because it failed to address mandatory spending limits by instead allocating additional funds to the Overseas Contingency Operations account, which are not subject to budget cuts.

This article was written by Jessica Schulberg for Huffington Post on June 5, 2015. Jessica Schulberg is a reporter covering foreign policy and national security for The Huffington Post. Previously, she was a reporter-researcher at The New Republic.