The country that shares the U.S. southern border is one of the few that has not recognized that Joe Biden will be the next president of the United States.
Latino lawmakers noticed.
Congressional Hispanic Caucus Chairman Joaquin Castro, a Democratic House member from Texas, and several other Latino lawmakers lashed out at Mexican President Andrés Manuel López Obrador for not acknowledging Joe Biden as president-elect.
López Obrador said Saturday that he would refrain from commenting on the U.S. elections until "all the legal matters have been resolved."
"This represents a stunning diplomatic failure by Mexico's President Andrés Manuel López Obrador at a time when the incoming Biden Administration is looking to usher in a new era of friendship and cooperation with Mexico," Castro tweeted Saturday in English and Spanish.
Castro, who is Mexican American, heads the House Foreign Affairs oversight subcommittee and has said he wants to head the full committee.
President Donald Trump is challenging the election results in several states. Election officials have said they have no evidence of fraud, pointing to the presence of representatives of both parties during the vote counts and the transparency of the process. Experts say Trump's efforts are unlikely to change the election results.
At least half a dozen other Democratic lawmakers joined Castro's criticism of López Obrador. Rep. Chuy García, D-Ill., who was born in Mexico, tweeted in Spanish, "Don't let the train pass you by." Most world leaders have recognized Biden's win.
Arizona Democratic state Sen. Martín Quezada said, "This is beyond disappointing."
Because of mutual interests, the relationship between the U.S. and Mexico will be fine, said Michael Shifter, president of the Inter-American Dialogue, a Washington-based think tank, but he said López Obrador's delay in congratulating Biden is not helpful.
"It's a mistake on his part that will affect the tenor of the relations at the beginning to some extent," Shifter said.
López Obrador, who took office in late 2018, has dealt with tough demands from Trump to stem illegal migration through Central America to the Mexican-U.S. border. Doing so kept tough tariffs on Mexico's products from going into effect.
The U.S., Mexico and Canada ratified the United States-Mexico-Canada Agreement to replace the North American Free Trade Agreement, helped in part by the Trump-López-Obrador relationship. Mexico avoided deep oil production cuts demanded by OPEC with some intervention by Trump.
López Obrador began his presidency promising a more humane approach to migrants. But he ended up using Mexico soldiers, National Guard forces and police to stem the flow of migrants, and he gave in to Trump's demands to have migrants wait for their U.S. asylum court dates in Mexico under the "Remain in Mexico" policy.
Mexican Foreign Minister Marcelo Ebrard told the Mexican newspaper Reforma that the government has been in contact with Biden's and Trump's teams and would remain in contact during the coming days.
"Whether it's keeping the [relationship] with Trump or establishing it with Biden, who has known President López Obrador since 2012, the objective will be to have the best possible relationship," Ebrard told Reforma.
Some said Biden offers a fresh take on U.S.-Mexican relations after Trump kicked off his 2016 campaign calling Mexican immigrants rapists, murderers and people bringing drugs into the country and pledged to build a wall along the entire Mexico border, which he would make Mexico pay for.
He said that Mexico's ties to the U.S. are strategic and that López Obrador has demonstrated how seriously he takes the relationship.
López Obrador's hesitation to acknowledge Biden as the president-elect stands in contrast to the reactions of most leaders in the region, except for Brazilian President Jair Bolsonaro, who is sometimes referred to as "the Trump of the Tropics."
Not all leaders congratulated Biden. Cuba acknowledged that the U.S. has a new president but did not mention Biden's name or congratulate him.