The Senate on Friday is expected to debate and vote on an amendment from Sen. Robert MenendezRobert MenendezThe Mideast-focused Senate letter we need to see Taiwan deserves to participate in United Nations The way forward on the Iran nuclear deal under President Trump MORE (D-N.J.) that would further tighten economic sanctions against Iran, just a year after Congress passed what many hailed as extremely tough measures against Tehran.

Menendez offered an amendment to the National Defense Authorization Act, and senators agreed by unanimous consent to take it up Friday. Menendez said his amendment is needed because of new evidence from the International Atomic Energy Association indicating that Iran appears to be adding centrifuge capacity and conducting explosives tests that could be used to detonate a nuclear weapon.

"Our message is clear. The window is closing. The time for the waiting game is over," Menendez said on the Senate floor late Thursday.

"Yes, our sanctions are having a demonstrable effect on the Iranian economy, but Iran is still working just as hard to develop nuclear weapons."

Votes on Iran sanctions legislation have typically sailed through both the House and Senate, reflecting the importance both chambers and both parties have put on discouraging Iran from developing nuclear weapons.

The Menendez amendment would build on the sanctions passed last year by designating Iran's energy, port shipping and shipbuilding sectors as "entities of proliferation," because of what he said was the role they play in Iran's "proliferation activities."

Designating those sectors means the U.S. would have to sanction transactions related to these sectors, including the blocking of property of third parties involved in these sectors.

His amendment would also sanction entities that supply certain commodities to Iran that are seen as contributing to Iran's shipbuilding capacity. These commodities include graphite, aluminum, coal, steel and software used to integrate industrial processes.

The sanctions approved last year hit Iran's central bank, but Menendez said his amendment would tighten those rules by preventing Iran from dodging those sanctions by accepting payment in precious metals.

Further, the language would redesignate Iran's broadcasting entity as a violator of human rights for broadcasting forced confessions and "show trials," Menendez said.