Morales, who ruled Bolivia for almost 14 years, fled on November 11, 2019, amid accusations of electoral fraud. He denied the allegations and declared himself the winner of the October 2019 vote, but was eventually forced to step down before leaving the country.
Arce, whom Morales had handpicked as his successor, has previously served as the country’s finance minister.
“When I left, I said: ‘We will come back, and we will be millions.’ Now we are back and we are millions,” Morales said after walking across the bridge connecting Bolivia and Argentina in Villazon, Bolivia, accompanied by Argentine President Alberto Fernandez.
The Bolivian interim government, which took power after Morales left the country, charged the former president with alleged sedition and terrorism, but the charges were dropped in October 2020.
Morales has previously announced his intention to move back to his home region of Chapare in Central Bolivia; he plans to arrive there on Wednesday, exactly 365 days after he left the country.
Bolivia has been badly hit by the coronavirus. The economy is also struggling. Unemployment has spiked since the pandemic began, and the International Monetary Fund is predicting a nearly 8% drop in GDP this year.
CNN’s Stefano Pozzebon reported from Bogota and Mitchell McCluskey reported from Atlanta. Ivana Kottasová wrote in London.