U.S. President Donald Trump has threatened to impose a 5 percent tariff on Mexico, accusing the country of long-term violations of a bilateral water-sharing treaty between the two neighbors. The warning was issued on Monday (December 8) through a statement posted on Trump’s social media platform, Truth Social.

According to Trump, the dispute revolves around obligations under the U.S.–Mexico water treaty, which requires Mexico to supply a fixed quantity of water to the United States over set cycles. He alleged that Mexico has failed to meet these commitments for years, resulting in severe consequences for farmers and ranchers in the southern U.S. state of Texas.

Trump claimed that continued water shortages have caused significant damage to crops and livestock, putting pressure on local agricultural economies. He argued that American farmers are bearing the cost of Mexico’s failure to honor the agreement.

In his statement, Trump asserted that over the past five years Mexico has accumulated a water debt exceeding 800,000 acre-feet. He said Washington has repeatedly raised the issue through diplomatic channels, but has received no satisfactory response from the Mexican side.

The U.S. president set a deadline of December 31, demanding that Mexico release at least 700,000 acre-feet of water, with the remaining balance to be delivered shortly thereafter. Trump warned that Mexico has yet to take any concrete steps, describing the situation as “a grave injustice to American farmers.”

He further escalated the warning by linking the issue to trade measures. Trump said he has already approved the necessary documentation to impose a 5 percent tariff on Mexican goods if Mexico does not immediately release the required water. “If Mexico fails to act, we will move forward with the tariff,” he said.

Mexico is one of the United States’ largest trading partners, and analysts caution that any new tariff could impact cross-border trade, supply chains, and bilateral relations. Experts also note that past water disputes between the two countries have typically been managed through negotiations under joint commissions rather than trade penalties.

As of now, the Mexican government has not issued an official response to Trump’s remarks. With the year-end deadline approaching, the situation is being closely monitored, as it could potentially trigger renewed diplomatic and trade tensions between Washington and Mexico.