WATCH: White House press secretary holds briefing after Mexico’s president confirms he’s skipping Summit of the Americas

Mexican President Andrés Manuel López Obrador confirmed Monday that he will skip the Summit of the Americas in Los Angeles, dealing a blow to the U.S.’ efforts to rally governments to work together to address surging migration in the hemisphere.

Watch the briefing in the player above.

López Obrador had been leading a chorus of mostly leftist leaders pushing the U.S. to invite Cuba, Nicaragua and Venezuela to the gathering taking place on U.S. soil for the first time since 1994.

Other leaders, including from Guatemala, Honduras and El Salvador – three big drivers of migration to the U.S. – have indicated they’ll stay away too.

The White House defended its decision to exclude certain countries, while also confirming López Obrador will visit Washington in July to meet with Biden. Press secretary Karine Jean-Pierre said there was “candid engagement” with the Mexican leader about the summit.

READ MORE: In blow to Biden, Mexican president to skip Summit of the Americas

“We do not believe that dictators should be invited,” Jean-Pierre said.

With so many no-shows, critics say the event risks turning into an embarrassment for President Joe Biden, who has struggled to reassert U.S. leadership in a region where mistrust of the U.S. runs deep and China has been made major inroads the past two decades as the U.S. foreign policy has been dominated by wars in the Middle East and now Russia’s invasion of Ukraine.

Jean-Pierre also answered questions on the work being done by lawmakers on Capitol Hill over new gun regulations.