WASHINGTON — Senators from both parties on Wednesday accused the Trump administration of overstepping its authority by pushing through arms sales to Saudi Arabia and other Arab allies in May without congressional approval, and vowed to reassert the role of Congress in reviewing weapons deals.

Lawmakers vented their frustration at a hearing with the State Department official overseeing arms sales, C. Clarke Cooper, telling him the administration had failed to make the case why $8 billion in weapons sales had to be expedited without time for congressional oversight.

"For whatever reason, the administration — in what seems to me a not fully baked decision-making process — decided to circumvent the law, decided to circumvent the constitutional responsibility of Congress and act unilaterally," said Republican Sen. Ted Cruz of Texas.

Cruz added: "And don't make the mistake of thinking that it is simply Democrats who are concerned about this."

If the administration attempted to bypass Congress again, Cruz said he would oppose the move and predicted other Republicans would as well.

Several Republicans have joined Democrats in supporting bills disapproving of the arms sales, but President Donald Trump has promised to veto the measures. Opponents would need to secure more Republican votes to overturn a Trump veto.

Congress usually has 30 days to review all arms sales. But on May 28, Secretary of State Mike Pompeo invoked a rarely used provision in arms control law to bypass Congress and declare an emergency to expedite the weapons deals, which he said were justified due to the threat posed by Iran.

Although the administration portrayed the arms sales as a matter of urgency to help Saudi Arabia, the United Arab Emirates and Jordan counter Iran, Cooper acknowledged after repeated questioning that the military hardware had yet to be delivered 47 days later.

Under questioning by Democratic Sen. Bob Menendez of New Jersey, Cooper also acknowledged that many of the necessary contracts between the U.S. and the Arab governments buying the weapons had not been wrapped up.

"What's the sense of the emergency?" asked Menendez.

The Democrat accused Cooper and the State Department of failing to treat Congress as a co-equal branch of government as enshrined in law. Menendez said that "since you began your tenure, the [State] Department has shown only disdain for Congress and the laws that govern our arms export programs."

Cooper defended the fast-tracked arms sales, saying it was a "one-time event." He said intelligence had indicated a growing threat from Iran and that events since the May 28 announcement had confirmed the danger, including the downing of an unmanned American surveillance aircraft by Iranian forces.

He also said Washington needed to ensure it was a reliable supplier of arms to its allies. Otherwise, Cooper said, U.S. adversaries such as Russia or China could usurp the U.S. as a security partner.

"In such an environment it is crucial that the United States remain the partner of choice and be trusted as a dependable provider of defense capabilities — including materiel — to our partners," Cooper said.

Sen. Chris Coons, D-Del., said that lawmakers on both sides of the aisle would not allow congressional oversight to be undercut and are prepared to vote to scale back the president's power to declare an emergency for arms packages.

If the administration fails to consult Congress, "I suspect this body will act and restrict or remove that ability for future emergency waivers altogether," Coons said.

The Senate Foreign Relations Committee recently backed a bill sponsored by Menendez and other lawmakers that would restrict the president's authority to invoke an emergency to skip congressional approval for arms deals. Under the bill, an emergency waiver could only be used for top-tier security treaty allies, including NATO countries, Australia, Israel, Japan, South Korea and New Zealand.

Coons and other senators also said patience had run out with Saudi Arabia, citing its human rights record, the killing of Saudi writer and Washington Post columnist Jamal Khashoggi and the conduct of its air war in Yemen.

Sen. Jim Risch, R-Idaho, chairman of the Senate Foreign Relations Committee, said the hearing illustrated a sense of exasperation among lawmakers and he urged the administration to reevaluate its approach to the Saudis.

"There is a lot of frustration right now," Risch said.

Risch, who usually supports President Trump in his public comments, on Wednesday proposed a bill that calls for a comprehensive review of U.S. relations with Saudi Arabia.

Risch's bill would deny U.S. visas to members of the Saudi royal family who serve in the government until the Trump administration certifies that Riyadh is making "demonstrable progress in addressing arbitrary detentions, forced disappearances, and torture of prisoners."

However, the bill would not seek to block arms sales and any travel bans would not apply to the Saudi crown prince, Mohammed bin Salman.

The CIA concluded that the crown prince ordered the killing of Khashoggi.

Risch said his bill might not go far enough for some senators but he said he hoped it could draw bipartisan support and prompt the administration to recalibrate its relationship with the Saudis.