The senators have sent a letter to two of Obama's highest-ranking cabinet secretaries stressing the importance of the hub.
"The economic links between Canada and the states of Vermont and New York are vital, and there is great potential to make them stronger still," they wrote to Secretary of State Hillary Clinton and Janet Napolitano, the homeland security czar.
"A smoother customs experience in Montreal will spur job creation and economic opportunities on both sides of the border."
The letter is from New York Democrats Charles Schumer and Kirsten Gillibrand, Vermont Democrat Patrick Leahy, as well as Bernie Sanders, an independent also from the so-called Green Mountain State.
The senators are pushing federal negotiators to move quickly to reach an agreement with Canada that they say would dramatically improve service on Amtrak's Adirondack line and could represent the first step in restoring service between the U.S. capital region and Montreal.
Officials on both sides of the border have been discussing such an initiative for years.
But now state representatives, officials from Amtrak and federal agencies from both countries are getting down to brass tacks, with a plan in place to open a pre-clearance customs and immigration centre at Central Station at some point in the future.
The facility would be staffed by both American and Canadian agents who would screen passengers travelling to and from the United States.
St. Albans, Vt., about 25 kilometres from the Canada-U.S. border, is now the final stop of Amtrak's so-called Vermonter train.
The passenger coach runs daily from the town to and from Washington, D.C., and various stops in between, including New York City. The Vermonter used to continue to Montreal until Amtrak discontinued the service in 1995.
The Adirondack service, meantime, connecting Montreal and New York, takes at least 11 hours, including delays of as long as two hours as agents come aboard the train at the Canada-U.S. border to screen passengers.
To great fanfare, U.S. President Barack Obama and Prime Minister Stephen Harper announced last year a border initiative aimed at easing congestion while improving security at the Canada-U.S. boundary.
Among the goals of the initiative was to establish pre-clearance facilities at train stations. The four senators want Montreal to be the first one out of the gate and are hoping for an agreement by the end of the year.