Cuba "expresses solidarity with its brother president Evo Morales", Foreign Minister Bruno Rodriguez said in a tweet, describing Morales as "a protagonist and a symbol of the rights of the indigenous peoples of our Americas".
Bolivian opposition lawmaker Jeanine Añez said Monday she plans to become head of the Senate following the resignation of Evo Morales and other senior leaders.
In a redrawing of Latin America's political landscape, the left has regained power in both Mexico and Argentina, though powerhouse Brazil retains a right-wing government.
The Mexican government's support has helped cement its emerging role as a bastion of diplomatic support for left-wing leaders in Latin America.
"I resign my post as president", the leftist Morales said Sunday in a televised address.
Morales' government collapsed yesterday after ruling party allies quit and the army urged him to step down, a tactic that Mexico's government and Mr Morales said was a "coup" because it broke with Bolivia's constitutional order.
And while acknowledging the military's role in Morales's ouster and that it "led to a risky power vacuum", the Post insisted it "was not a coup in the usual sense".
Furthermore, the Mexican government noted that for humanitarian reasons and by virtue of the emergency situation that Morales faces in Bolivia, where his life and integrity are at risk, he is being granted political asylum in Mexico. He stepped down following the demands of the country's armed forces, opposition and trade unions.
Morales stepped down Sunday under pressure from Bolivia's military following weeks of violent protests fed by allegations of electoral fraud in the October 20 presidential election that he claimed to have won.
A formal designation of a coup would require the United States to cut most aid to Bolivia, which had uneasy relations with the United States under Morales, especially over his championing of indigenous coca farmers.
The United States authorized non-emergency US officials to leave on Bolivia Tuesday, citing "ongoing political instability" in the nation. Military fighter jets flew repeatedly over La Paz in a show of force that infuriated Morales loyalists who were blocked by police and soldiers from marching to the main square.
After nightfall, there were reports of tensions in La Paz and the neighboring city of El Alto, with reports of looting and burning of public property and some houses. Rock-throwing demonstrators also clashed in Cochabamba and other cities.
"It's very worrying. There was a lot of fear and panic last night".
She spoke after arriving at the legislature in La Paz under heavy guard.
According to the Bolivian constitution, the vice president is next in line to take power when the president steps down. Its principal victims will be not Morales and his fellow politicians, but the masses of Bolivian workers, peasants and oppressed. The military made a decision not to deploy in the streets because "they didn't want to take lives", said Mesa who finished second in the contested October vote.
After the opposition called for canceling the polls, Morales announced there would be new elections, but opposition supporters said they would continue protests until an election without Morales was held. Two government ministers in charge of mines and hydrocarbons, the Chamber of Deputies president and three other pro-government legislators announced their resignations.
She also said she would convene a legislative session on Tuesday to consider accepting the formal resignation of Morales, and that new presidential elections could soon follow.