MEXICO CITY—Mexicans reacted angrily to news U.S. President Donald Trump would unveil details Wednesday of his plan to build a border wall between both nations, particularly since the announcement comes on the day top Mexican officials meet with U.S. administration representatives to discuss the troubled bilateral relationship.

“This is an insult to those Mexican officials, to the president of Mexico and to all Mexicans,” Jorge Castaneda, a former foreign minister, said in a televised interview. “It’s a way of making them negotiate under threat, under insults, and it should lead (Mexican) President (Enrique) Peña Nieto to cancel his trip next week.”

Mr. Peña Nieto is due to meet Mr. Trump on Jan. 31 in the first meeting between both men since Mr. Trump briefly visited Mexico as a candidate last summer, a visit that caused controversy south of the border and hurt the Mexican president’s standing in the polls.

The announcement of Mr. Trump’s plans for a border barrier comes at a time of deepening strains between the nations over a variety of issues, including Mr. Trump’s plans for the wall, his intention to renegotiate or pull out of the North American Free Trade Agreement, and his attacks on U.S. companies that build new factories in Mexico.

Mexican Foreign Minister Luis Videgaray and Economy Minister Ildefonso Guajardo are meeting Wednesday in Washington with top Trump administration officials, including chief of staff Reince Priebus, senior adviser and son-in-law Jared Kushner, and national security adviser Michael Flynn.