WASHINGTON ― President Donald Trump made good Saturday on his decision to withdraw the U.S. from the Open Skies Treaty, but it looks like President-elect Joe Biden, who opposed that move, may have a path to revive the pact.

Because it could take months for the Air Force to move through the legal and bureaucratic processes necessary to decommission the Boeing OC-135B planes flown from Offutt Air Force Base, Neb., to execute the treaty mission, it appears the Biden administration would have ample time to reverse course. The treaty permits 30-plus nations to conduct unarmed, observation flights over each other’s territory.

“The final decision on disposition of Open Skies Treaty resources has not yet been made,” an Air Force official told Defense News on Tuesday. “The 45th Reconnaissance Squadron at Offutt AFB is still flying local OC-135 missions at a greatly reduced rate in order to maintain aircrew qualifications, while the Air Force continues to assess options for realigning, repurposing, or retiring the two 1960s-era OC-135B aircraft, as well as other associated equipment in accordance with DoD guidance.”

Despite reports the Trump administration might be scrambling to get rid of the OC-135B planes, a congressional source said the Air Force plans to keep the planes until the end of fiscal 2021 and service leaders had yet to make a firm decision about what to do with them.

The administration, with backing from a number of Republican lawmakers, announced in May it wanted out of the treaty because Russia was violating the pact, and imagery collected during the flights can be obtained quickly at less cost from U.S. or commercial satellites. U.S. allies tried to forestall the move and generally argue the treaty is a valuable channel for transparency and dialogue between Russia and the United States, the world’s top two nuclear superpowers.

Secretary of State Mike Pompeo said at the time that the U.S. and allies in the pact lived up to their treaty commitments and obligations, but “Russia has flagrantly and continuously violated the treaty in various ways for years. This is not a story exclusive to just the treaty on Open Skies, unfortunately, for Russia has been a serial violator of many of its arms control obligations and commitments.”

The overflights were set up decades ago to promote trust and avert conflict, and Biden has panned the idea of a withdrawal, saying it would “exacerbate growing tensions between the West and Russia, and increase the risks of miscalculation and conflict.”

Given the partisan dynamics of the Senate, it’s unclear the upper chamber could muster the two-thirds majority required to re-ratify the treaty. However, Biden may be able to re-enter the treaty in a way that would not require formal advice and consent from the Senate, according to Alexandra Bell, the senior policy director at the Council for a Livable World.

One path is for Biden to craft an executive agreement requiring simple majority approval in both houses. Parties to the treaty would need to be on board and Congress would also need to approve funds for continued U.S. participation. Trump’s potential scuttling of the planes “might complicate diplomatic options, but the incoming Biden administration will likely make choices about the future of the treaty based on national security considerations, not the Trump team’s ‘salt the earth’ behavior,” Bell said.

Democrats and some Republicans have urged Biden to rejoin the treaty once in office.

In a statement to Defense News, Rep. Don Bacon, R-Neb., a retired Air Force brigadier general who commanded the 55th Wing at Offutt, noted that the OC-135s can be used to collect unclassified images during disaster response missions and other roles in support of civil authorities. They were used in the aftermath of the 2010 earthquake in Haiti to assess the damage and direct resources, he said.

“My hope is that the move to end Open Skies will be reversed as it is an essential operation. In the meantime, we should not make any moves to scrap the 135′s because the OC-135B aircraft already fill important additional roles above and beyond the Open Skies treaty,” Bacon said.

“The small cost of the two Open Skies aircraft is offset by the observations they enable, as well as the benefits they deliver outside of the treaty mission. Considering these benefits, and the potential that we may yet rejoin the treaty, it’s important to maintain the aircraft for the time being.”

Democrats have ripped Trump over a broader pattern of discarding arms control and non-proliferation agreements. Some question the legality of Trump’s pullout from Open Skies, citing language in the 2020 National Defense Authorization Act that reaffirmed congressional support for the treaty and mandated the administration justify a withdrawal four months before any formal notification of withdrawal can take place.

This week, Senate Foreign Relations Committee ranking member Bob Menendez, D-N.J., called the administration’s withdrawal “reckless” and encouraged Biden to rejoin the pact once Biden is inaugurated.

There are Senate Republicans who would likely oppose a reentry. Senate Airland Subcommittee Chairman Tom Cotton, and Sens. Ted Cruz and Richard Burr, have worked in various ways to support a withdrawal. Cotton has argued funding for the OC-135 should go toward nuclear weapons modernization.

“I am pleased that the Trump administration has taken the final and necessary step to formally withdraw from this costly and outdated agreement,” Cruz said in a statement Monday. “Russia will no longer be able to use this treaty to use our skies to spy on the American people.