MEXICO CITY — Mexican President Andres Manuel Lopez Obrador has strongly criticized the U.S. government for what he describes as “interference” in Mexico’s internal affairs, particularly through the funding of a Mexican NGO opposed to his administration.

According to Burkina Information Agency, in a letter dated August 16 and presented during his daily press conference on Monday, Lopez Obrador denounced the financial support provided by U.S. government agencies to the NGO Mexicans Against Corruption and Impunity. The organization has been a vocal critic of Lopez Obrador’s government.

“This procedure is totally offensive and contrary to relations respectful of sovereignty,” Lopez Obrador wrote in the letter addressed to U.S. President Joe Biden. He urged Biden to take steps to cease the activities of the U.S. Agency for International Development (USAID) that support such practices, which he argues threaten Mexico’s constitutional principles of non-intervention and self-determination.

Lopez Obrador, who is nearing the end of his term in September, has repeatedly expressed concerns over U.S. financial support to opposition groups in Mexico, viewing it as an infringement on the country’s sovereignty.