With the summer tourism season fast approaching, New Hampshire’s two U.S. representatives are warning about potential impacts here from the federal Department of Homeland Security’s plan to move hundreds of officers from the northern border to deal with the immigration crisis at the southwestern border.

U.S. Rep. Ann McLane Kuster, D-N.H., said she has heard from U.S. Customs and Border Protection (CBP) personnel in New Hampshire “who have serious concerns about the potential impact staff changes could have on public safety.”

Kuster said she is also concerned about possible disruptions to operations at the Canadian border. “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,” she said in an email. “I will work with my colleagues whose states and districts share a border with Canada to address this serious issue.”

Rep. Chris Pappas, D-N.H., echoed Kuster’s concerns. “Our state is a tourist destination, and we rely on the flow of goods and people between New Hampshire and our neighbor to the north, Canada,” he said in an email. “By creating longer lines at our ports of entry, we may be discouraging people from visiting or doing business in New Hampshire.”

Pappas said he and Kuster will work together “to protect our state’s interests while also supporting efforts to address the immigration challenges along the Mexican border.”

Earlier this month, the two joined 11 House colleagues from northern states in a bipartisan letter to acting DHS Secretary Kevin McAleenan, asking him to immediately rescind the transfer of CBP officers from the border with Canada. They warned that the plan will have “economic and security implications” for cross-border travel and trade, and cause “excessive delays” at border crossings.

The letter notes that the northern border between Canada and the United States, at 5,525 miles, is the world’s longest land boundary between two countries. Approximately 400,000 people and more than $1.6 billion in goods cross the border daily through more than 120 ports of entry, it states.

With ports of entry facing increased volume as the summer approaches, the decision to transfer CBP officers to the southern border “makes it increasingly more difficult for the agency to meet their core mission requirements at the border, which include effectively securing U.S. points of entry and safeguarding and streamlining lawful trade and travel,” they wrote.

Michael McCarthy, public affairs officer for U.S. Customs and Border Protection, said a total of 731 CBP officers either have been, or soon will be, reassigned from airports, seaports and land ports of entry for “temporary deployment” to the southern border. He said he could not release information about how many officers would be reassigned from specific locations, such as the border crossings in Pittsburg and Derby Line, Vt., where many New Hampshire drivers enter Canada.

But he stressed that the primary mission for CBP officers at ports of entry remains border security and enforcement. “We will never compromise that mission,” he said. “That will be our primary mission at the northern border and we will work to minimize any impact to travel times or wait times.”

McCarthy said his agency has not heard of longer wait times at northern border crossings to date. And he said, “Since we are able to move our officers and deploy them, we have ways to hopefully mitigate any potential wait times.”

McCarthy said the Boston field office of CBP, which oversees all of New England and includes about 1,000 officers, previously has supported temporary duty assignments as needed, such as disaster relief operations after Hurricanes Harvey and Maria.

Tony Reardon is national president of the National Treasury Employees Union (NTEU), which represents CBP officers, agriculture specialists and trade enforcement personnel who work at the ports of entry. In a statement, Reardon said those stations “have been severely understaffed for years.”

“So it stands to reason that sending hundreds of CBP officers to the southwestern border for temporary duty would further hinder operations at their home ports, including those along the northern border,” he said.

“These temporary duty assignments to the southern border put a strain on the CBP employees, their families and their coworkers,” Reardon said. He said the union will work to make sure that assignments are implemented fairly and that CBP employees “are provided adequate housing and safe working conditions while they are deployed.”

The NTEU joined a coalition of business and industry groups that recently sent letters to members of Congress, calling for a hiring surge at Customs and Border Protection. The groups, which include the U.S. Chamber of Commerce, the U.S. Travel Association and the American Association of Port Authorities, said border delays discourage international visitors, increase supply-chain costs, and result in lost wages, jobs and tax revenue. They said research shows that border delays cost the U.S. economy more than $5 billion a year.

A bill recently introduced in Congress would authorize an increase of 600 CBP officers annually to meet the agency’s current and future staffing needs.