President Donald Trump’s threat that he will close the U.S.-Mexico border if Congress refuses to build a wall could have devastating economic implications even in Massachusetts – which does more than $6 billion in trade a year with Mexico, experts said.

In his latest case of presidential brinksmanship, Trump tweeted Friday he will shut the Mexican border if Congress does not fund a border wall as the federal government continues to be partially shut down.

Mexico is Massachusetts’ second largest trading partner, after Canada.

Last year, Bay State businesses exported $2.5 billion to Mexico, according to data from the U.S. Census Bureau, though it is unclear how much of that went by truck over the border. The state also imports more than $3.7 billion from Mexico. The bulk of the trade is in electronic components and medical devices that are both imported and exported – and are vital to the state’s hospitals, research labs and electronics industries.

Robert Fisher, former director of Mexican affairs in the Office of the U.S. Trade Representative, told the Herald the economic impact would be nationwide: “You end up with a major disruption on both sides in trade. It’s about $1.3 billion a day in land trade between the United States and Mexico in 2017.”