(JNS) A bipartisan group of members of Congress sent a letter last week to U.S. Secretary of State Mike Pompeo and U.S. Defense Secretary Mark Esper, stating that withdrawing U.S. troops from the Multinational Force and Observers (MFO) in Egypt’s Sinai Peninsula would be “a grave mistake.”

The May 13 letter came in response to a Wall Street Journal report earlier this month that Esper has been leading a push to end the decades-long U.S. participation in the 13-country peacekeeping force, which seeks to implement the 1979 Israel-Egypt peace treaty.

“The U.S. Mission to the MFO (Multinational Force & Observers) is one of many missions DoD is currently assessing,” said U.S. Department of Defense spokesperson Navy Cmdr. Sean Robertson in a statement to the outlet.

The proposal to withdraw the United States from the peacekeeping force, which consists of more than 400 U.S. troops out of 1,100 troops from all over the world, has been met with opposition from Israel and the State Department.

“The MFO has been vital to the peace treaty’s durability. Since its establishment in 1981, the MFO has supervised the implementation of the security provisions of the Egyptian-Israeli peace treaty and employed best efforts to prevent any violation of its terms,” said the letter.

“While the current Egyptian and Israeli governments both recognize the importance of the peace treaty and have every interest in sustaining it, the MFO’s oversight and mediation ensures that disagreements between the two sides are resolved diplomatically and discreetly.”

The letter went on to state that “the MFO’s credibility to both the Egyptian and Israeli governments depends, in large part, on America’s continued leadership role in the MFO, including the U.S. military men and women who are currently deployed to the Sinai Peninsula. The U.S. force contribution to the MFO is also critical to encouraging 12 other U.S. partners to contribute their own troops to the organization. Today, those other countries’ contributions represent more than 60% of the MFO’s overall force.”

The letter was signed by Sen. Jim Risch (R-Idaho), chairman of the Senate Foreign Relations Committee; Sen. Robert Menendez (D-N.J.), the committee’s ranking member; Rep. Eliot Engel (D-N.Y.), chairman of the House Foreign Affairs Committee; Rep. Michael McCaul (R-Texas), the committee’s ranking member; Sen. James Inhofe (R-Okla.), chairman of the Senate Armed Services Committee; and Sen. Jack Reed (D-R.I.), the committee’s ranking member; and joined by a bipartisan group of congressmen and women.