An overwhelming bipartisan majority of lawmakers called on President Trump to exert American pressure in Syria, underscoring threats to Israel’s security and U.S. interests if Iranian and Russian influence dominate the region and terrorist groups operate with impunity.

The letter, sent Monday and signed by almost 400 members of Congress from both the House and Senate, calls for the president to reaffirm support for Israel, pressure Iran and Russia related to their activities in Syria and increase sanctions on Hezbollah.

Senators James Risch (R-ID) and Bob Menendez (D-NJ), chairman and ranking member of the Senate Foreign Relations Committee, and Reps. Eliot Engel (D-NY) and Mike McCaul (R-TX), chairman and ranking member of the House Foreign Affairs Committee, co-authored the letter.

While signatures are missing from House Republican leadership, Minority Leader Kevin McCarthy (R-TX), Minority Whip Steve Scalise (R-LA), and Conference Chair Liz Cheney (R-WY), a leadership source said the letter had not been circulated to them in time to sign.

Reached for comment on Scalise’s position on U.S. policy in Syria, his spokeswoman Lauren Fine said the congressman “supports the issues raised and shares these concerns. The security of Israel is of utmost importance to him, and he is confident President Trump shares those concerns as well.”

The letter comes following a report by the Syrian Working Group, a team of foreign affairs experts selected by bipartisan members and tasked with analyzing U.S. policy in Syria. The report, sent to Senate and House leadership in early May, lays out recommendations and challenges on U.S. engagement in Syria, including a continued military presence and engagement with the Syrian Kurdish Forces to counter the threat of ISIS and other terrorist groups, while supporting Israel against Iranian capabilities in the country.

Rep. Dan Crenshaw (R-TX), who signed the letter, tells Jewish Insider that he agrees with the Trump Administration’s current approach. “Generally speaking I think we like what we see,” emphasizing a small, strategic military presence and support for Israel.

Rep. Jeff Van Drew (D-NJ), also a signatory, tells JI that current U.S. policy doesn’t go far enough. “I think we could do more.”