Iranian military leaders on Monday celebrated Hamas’ use of advanced long-range rockets that were supplied to the terror group by the Iranian regime.

Iran’s role in arming Hamas militants with more sophisticated artillery capable of reaching deep into Israel has fueled concerns among lawmakers that U.S. negotiators are not doing enough to address Iran’s support for terror during ongoing nuclear discussions.

Israeli and United Nations officials have confirmed that Hamas is firing rockets on civilians provided to it by Iran.

A Senior Iranian Revolutionary Guard Corps (IRGC) general praised Hamas’ rocket attacks on Monday and warned that between Hamas and other Iranian-backed terror groups, "all Zionists are within the range of the resistance's missiles."

"The defense capacity and capabilities of the Islamic resistance and Hamas forces has left no safe place for the Zionists in the occupied territories," General Ramezan Sharif, head of the IRGC’s public relations department, said in public remarks Monday.

Palestinian terror groups, including Hamas and other Iranian-backed groups, are well armed and can strike Jewish civilians inside and outside of Israel, Sharif said.

"The quality and trend of action of the Palestinian resistance movement in recent days indicates that the defensive and offensive power of Hamas, Ezzedin Al-Qassam, and Quds brigades forces have increased so much that one can dare say that all Zionists are within the range of the resistance's missiles," Sharif was quoted as saying by Iran’s semi-official Fars News Agency.

The Quds brigades are an elite Iranian force that trains terrorists, including Hezbollah, and is responsible for waging terror attacks across the Middle East against Western targets.

Iran’s arming of Hamas is beginning to receive attention at the highest levels of the U.S. government as the terror group continues to barrage Israel with more sophisticated rockets aimed at Tel Aviv, Jerusalem, and even the northern city of Haifa.

House lawmakers explicitly referenced Iran’s role in the conflict in a recent resolution supporting Israel’s right to self-defense.

"Iran has long provided material support to Hamas and Palestinian Islamic Jihad, including assistance that has enabled these terrorist organizations to produce longer-range rockets capable of striking Tel Aviv and Jerusalem," the resolution stated.

Rep. Ed Royce (R., Calif.), the author of the resolution’s Iran-related language, said the regime’s proud support of Hamas should give U.S. negotiators "pause" and indicates that Tehran cannot be trusted to abandon its nuclear program.

"The failure of the government in Iran to adjust its behavior … gives us pause on how much seriousness they’re putting into these [nuclear] negotiations," Royce was quoted as saying late Friday during a meeting with reporters.

The State Department has said that it shares Congress’ concerns, but that the issue is not being broached during nuclear talks with Iran, which are set to expire on July 20.

State Department spokeswoman Jen Psaki confirmed in a July 9 briefing that she is "not aware" of the issue of Iran’s support for Hamas being mentioned during talks.

"The focus is on the nuclear issue," she said. "There’s plenty to discuss on that particular issue."

"How do you discuss just nuclear issues with Iran when all this is going on, them supplying rockets to Hamas or Syria, and also possible destabilizing efforts in Iraq?" a reporter followed up, according to the official transcript.

"Obviously resolving the nuclear issue and preventing Iran from acquiring a nuclear weapon is not the only issue we have with Iran," Psaki said. "But it’s such an important issue and it’s one that’s vital to our national security interests and to the security of the region that we feel a focus on that at these discussions is absolutely appropriate."

A State Department spokesman on Monday did not respond to further inquiries about conversations it may or may not have had with Iran about Hamas.

House insiders working on the nuclear issue have expressed frustration over the administration’s hesitance to broach Iran’s larger support for terror groups such as Hamas.

"As the administration continues nuclear negotiations with Iran—the world’s largest state sponsor of terrorism—its proxy Hamas is firing hundreds of rockets at population centers in Israel," one senior House aide told the Washington Free Beacon. "It’s becoming increasingly harder for the president to ignore the Iran-funded terrorism coming out of the Gaza Strip, which thus far he’s brazenly overlooked in order to preserve prospects for a final nuclear agreement with Iran."