The Central American country of 6.3 million people goes to the polls on February 4.

Under heavy security, Bukele and his running mate Vice President Felix Ulloa submitted their papers at the Supreme Electoral Tribunal (TSE) in the capital San Salvador, where AFP journalists saw dozens of supporters chanting "Nayib!" and "re-election!"

Bukele, 42, announced last year that he would seek another term in office after the Supreme Court allowed him to seek re-election, sparking intense debate over its constitutionality.

Critics have questioned the legality of a second consecutive term.

The Salvadoran constitution imposes single-term limits on candidates for presidential elections, barring anyone from running who "has served as President of the Republic for more than six months, consecutive or not" within the six months before the presidential period.

Bukele's right-wing New Ideas (NI) party has endorsed his quest to retain power.

The judges on the court were appointed by Congress, which is controlled by the president's New Ideas party.

Bukele, the former mayor of San Salvador and a high-profile bitcoin promoter, broke three decades of two-party dominance in Salvadoran politics with his victory in 2019.

A recent poll conducted by the Center for Citizen Studies at the Francisco Gavidia University gave New Ideas nearly 70 percent support, compared to just over 4 percent for its closest competitor.

Bukele's war against violent street gangs has won him the plaudits of the population, despite heavy criticism from human rights organizations over mass trials and arrests without warrants. 

Rights groups, the United Nations, and the United States have all expressed alarm over arbitrary arrests, inhumane prison conditions, and growing authoritarianism in El Salvador.