Lawmakers fear major delays and disruption this summer at northern border crossings which could seriously impact trade and tourism.
U.S. Customs and Border Protection is shifting more than 700 agents to the south to help stem the flow of people at the Mexican border.
They are being moved from land border checkpoints, sea and airports.
Tourism operators, many of which rely heavily on Canadian travelers, say any delays through staff shortages could seriously hamper their business.
Last week more than a dozen bipartisan members of Congress from six northern states wrote to acting Homeland Security Secretary Kevin McAleenan voicing their concerns.
"The decision to deploy northern border CBP officers to the southern border makes it increasingly more difficult….. to effectively secure U.S. points of entry and streamline lawful trade and travel," the letter said.
It doesn’t appear there will be any reinforcements from elsewhere to the northern border, which measures more than 5,000 miles.
"Tourism is central to our economy in the Granite State and I have serious concerns about any disruption in the efficiency of operations at the Canadian border," New Hampshire Democratic Rep. Annie Kuster said.
"Moving Customs and Border Protection personnel away from our northern border has the potential to impact U.S.-Canadian commerce and tourism just as we enter the busy summer months."
