WASHINGTON (Reuters) -The U.S. Commerce Department said on Monday it was withdrawing from a 2019 deal suspending an anti-dumping duty investigation on fresh tomatoes from Mexico, and that it will issue duties of 17.09% on most of those imports from the U.S. neighbor.

Antidumping duties are calculated to measure the percentage by which Mexican tomatoes have been sold in the United States at "unfair prices," the Commerce Department said in its statement.

President Donald Trump on Saturday had separately threatened to impose a 30% tariff on imports from Mexico starting on August 1, after weeks of negotiations with the major U.S. trading partner failed to reach a comprehensive trade deal.

Mexico's agriculture ministry and economy ministry did not immediately respond to a request for comment.

Mexico said in April it was confident that it can renew the tomato agreement with the United States. Washington had said in April that it intended to withdraw from the deal.

The agreement, which regulates Mexican tomato exports to the U.S. in a bid to allow U.S. producers to compete fairly, was first struck in 1996 and last renewed in 2019 to avert an anti-dumping investigation and end a tariff dispute.

U.S. Commerce Secretary Howard Lutnick said on Monday that "for far too long our farmers have been crushed by unfair trade practices that undercut pricing on produce like tomatoes."

According to official figures, Mexico exported $3.3 billion of tomatoes last year, the vast majority to the U.S.

(Reporting by Kanishka Singh in Washington; Editing by Mark Porter and Lincoln Feast.)