President Trump is poised to withdraw from a landmark Cold War missile treaty with Russia and there is little Congress can do to stop the move, experts say. But they can cut off funding for new missiles, if the administration decides to go that way.

The White House’s plan to leave the Intermediate-Range Nuclear Forces Treaty drew early outcry over the weekend from Sen. Bob Menendez, D-N.J., the ranking member on the Senate Foreign Relations Committee, and Sen. Rand Paul, R-Ky., a member of the committee.

“Congress must now put partisan bickering aside to constrain this administration’s efforts to destroy long-standing arms control agreements, prevent a nuclear arms race and prioritize the security of all Americans,” Menendez said in a statement.

So far, the administration has announced only its intent, saying the Russians have been cheating by deploying a missile system that violates the INF Treaty. Trump could give an official notification of withdrawal as soon as this week, which would start a six-month countdown until Washington's exit.

“It's an executive power that has long been exercised by presidents, and attempts to restrict a president's constitutional authority, even in the form of a statute, could well be unconstitutional,” Melanie Marlowe, a fellow at Carnegie Mellon University’s Institute for Politics and Strategy, wrote in an email. “Members of Congress who have tried to litigate their treaty policy differences with the president have been disappointed every time.”

In 2002, former Rep. Dennis Kucinich, an Ohio Democrat, and a group of House lawmakers sued President George W. Bush over his withdrawal from an anti-ballistic missile treaty originally signed with the Soviet Union. That case was thrown out of court.

The Constitution is silent on the president’s specific power to break treaties that were ratified by the Senate, but over the past century administrations have consistently maintained that chief executives can withdraw from agreements such as the INF Treaty, according to the Congressional Research Service.

“Treaties are typically the purview of the executive, and thus Congress can do very little to stop the administration's plan to withdraw from the INF,” Caroline Dorminey, a policy analyst with the Cato Institute’s defense and foreign policy studies department, wrote in an email.

However, when it comes to constraints, lawmakers such as Menendez could still have levers to pull in the months ahead to rein Trump in if the treaty is swept away.

The administration and the Pentagon are dependent on Congress to fund any new U.S. missile systems prohibited by the Cold War agreement. The treaty bans any testing or deployment of nuclear and conventional ground-launched ballistic and cruise missiles with ranges of 500 to 5,500 kilometers, which is 310 to 3,417 miles.

“Congress certainly has a role, but it is on the policy side about what comes next. If Trump really wants to exit INF he can, but Congress can appropriate, or fail to appropriate, money and otherwise shape what the United States does or does not do in terms of ground-launched missiles of intermediate range,” said Marlowe.

The Senate would also have to ratify any new missile treaty with the Russians that could replace the older agreement.

“It will be a very good thing if this display of will by the administration was to lead into some replacement arrangement. I don’t know what that is going to be,” said Thomas Karako, a senior fellow and director of the Missile Defense Project at the Center for Strategic and International Studies.

The U.S. has charged the Russians with deploying the SSC-8 missile system, also known as the Novator 9M729, and has been trying to prod it back into treaty compliance since 2014.

Meanwhile, Congress has been encouraging the Pentagon for several years to look into developing its own new missile systems to counter the Russian system.

“This is a treaty that the writing has been on the wall as of late. There are just too many ways to get around it, too many violations by the Russians, and just too much demand signal for intermediate-range strike of various forms,” Karako said.

The long-building U.S. frustration with the violation seems to have reached a breaking point with the Trump administration. National security adviser John Bolton, a critic of the treaty, was in Moscow on Monday and may have been laying the groundwork for a withdrawal.