WASHINGTON -- Aiming to prove their commitment to Israel, senior U.S. lawmakers are backing bipartisan legislation that would slap Iran with new sanctions while maintaining rigorous enforcement of the landmark nuclear deal.

The measures, unveiled ahead of the opening of the annual American Israel Public Affairs Committee conference, seek to build consensus among Republicans and Democrats who are so often bitterly at odds on domestic issues.

“The United States will stand with Israel,” Senate Majority Leader Mitch McConnell said at the conference Tuesday. But the Kentucky Republican criticized the nuclear agreement as a “windfall” for Tehran that prevented the U.S. from taking more aggressive steps against Iran.

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“But today we can take a different approach,” McConnell said. “Today, we can combat Iran’s capability to fund, arm, and train terrorists like Hezbollah, Hamas, and its proxies in Syria.”

In exchange for Tehran rolling back its nuclear program, the U.S. and other world powers agreed to suspend wide-ranging oil, trade and financial sanctions that had choked the Iranian economy.

The House bill, which is co-sponsored by House Majority Leader Kevin McCarthy and Minority Whip Steny Hoyer, targets Iran’s “illicit” ballistic missile development program. The measure would shut out of the international financial system Iranian and foreign companies involved in the missile program - along with the banks that back them.

The Senate legislation imposes mandatory sanctions on people involved in Iran’s ballistic missile program and anyone who does business with them. The measure also would apply terrorism sanctions to the country’s Revolutionary Guards and enforce an arms embargo.

The measure is supported by Sen. Bob Corker of Tennessee, the Republican chairman of the Foreign Relations Committee, and Sen. Ben Cardin of Maryland, the panel’s top Democrat.

“To combat these threats, we must harness every instrument of American power,” House Speaker Paul Ryan said at the conference Monday. “We must work with our allies - and Israel in particular - to counter this aggression at every turn.”

In the opening days of the conference, Israeli leaders hoping Trump would be a rubber stamp for the Jewish state heard plenty of reassuring rhetoric. Missing from the agenda so far, however, were concrete steps advancing the Israeli government’s top priorities.

The Iran nuclear deal, so despised by Israel and congressional Republicans, is solidly in place. The U.S. Embassy is no closer to moving to Jerusalem from Tel Aviv, as Prime Minister Benjamin Netanyahu’s government wants. And as it has under past presidents, Washington is still telling Israel to slow settlement construction.

It is making for an unusual AIPAC conference, one relieved of the strains that marked the last years of President Barack Obama’s tenure, but also filled with significant uncertainty.

Netanyahu on Monday called the U.S.-Israeli relationship “stronger than ever.”

His ambassador to the U.S., Ron Dermer, said a day earlier that for the first time in years or even decades, “there is no daylight between our two governments.”

Vice President Mike Pence said he and Trump “stand without apology for Israel and we always will.”

But it’s too early to tell whether Trump will ultimately fulfill Israel’s wishes. And there are indications he’s reconsidering several stances adopted during the campaign.

As a candidate, Trump repeatedly vowed to be the president to finally relocate the U.S. embassy to Jerusalem, which Israel considers its capital. As Pence said Sunday, that unequivocal promise has morphed into Trump now “giving serious consideration to moving the American embassy.”

While candidate Trump said he’d renegotiate or dismantle the Iran nuclear deal, which Israel fiercely opposes, President Trump’s administration is continuing to implement the accord while examining whether it should stand.

On Iran’s missile program, however, Trump has expanded U.S. sanctions. The administration last month responded to a missile test by hitting 25 people and entities with sanctions. But backers of the new legislation want the president to go further.