Sen. Marco Rubio is not on board with President Donald Trump's new trade deal with Canada and Mexico.

Trump ceremoniously signed the new agreement, called the U.S. Mexico Canada Agreement, in Buenos Aires this morning with Canada Prime Minister Justin Trudeau and Mexico's President Enrique Peña Nieto.

However, the agreement must still be approved by Congress and already some lawmakers have expressed concerns. Count Rubio among them.

Rubio tweeted Friday that the deal as drafted will "put Florida seasonal vegetable growers out of business."

Rubio has been critical of the draft agreement for months. He has accused Mexico farmers of getting around United States trade rules to "dump" warm-weather fruits in here. That's especially problematic for Florida growers, he has said, because the state grows much of the same produce.

Last year, Rubio said any new trade agreement should increase "oversight and enforcement" of illegal trade practices and that Mexico should have to raise its minimum labor and environmental standards to "limit excessive and unfair production cost advantages" over U.S. farmers.