UN Secretary-General Antonio Guterres on Monday urged El Salvador to respect the separation of powers after its parliament, newly controlled by President Nayib Bukele's party, dismissed the attorney general and top judges deemed hostile to the populist leader.

The new parliament, dominated by Bukele's allies, on Saturday voted to dismiss all five judges of the Constitutional Chamber, one of four organs of the Supreme Court, for allegedly issuing "arbitrary" judgments.

"The Secretary-General calls for respect of constitutional provisions, the rule of law and the division of powers, with a view to preserving the democratic progress achieved by the Salvadoran people since the signing of the peace agreement," Guterres's spokesman Stephane Dujarric told reporters.

But Bukele on Monday suggested the possibility of continuing to remove officials.

"The people did not send us to negotiate. They are leaving. All of them," the young president tweeted.

The New Ideas party, which Bukele founded, gained an outright parliamentary majority in February's elections.

Until then, Bukele, elected in 2019 for a five-year term, had faced difficulty getting programs approved in a parliament dominated by two opposition parties -- the right-wing Arena and the leftist FMLN.

El Salvador's President Nayib Bukele had faced difficulty getting programs approved in a parliament dominated by two opposition parties
El Salvador's President Nayib Bukele had faced difficulty getting programs approved in a parliament dominated by two opposition parties AFP / STANLEY ESTRADA

His detractors have long accused him of authoritarian tendencies, and observers had warned that an election landslide for New Ideas could give Bukele undue power.

The 39-year-old, who often sports jeans and a leather jacket in public with a baseball cap worn backwards, has clashed repeatedly with the Supreme Court and the public prosecutor's office.

The Constitutional Chamber had shot down several emergency measures proposed by Bukele to manage the coronavirus epidemic, finding they violated fundamental rights. He reacted furiously.

The dismissals have been criticized by the Salvadoran opposition, the Organization of American States, various NGOs and the US government.

US Vice President Kamala Harris said Washington had "deep concerns" for democracy in El Salvador following the vote to remove the judges.

"An independent judiciary is critical to a healthy democracy -- and to a strong economy," she tweeted late Sunday.

Hours earlier, Secretary of State Antony Blinken spoke to Bukele by telephone, expressing Washington's "grave concern" and "noting that an independent judiciary is essential to democratic governance," according to spokesman Ned Price.

He said Blinken also criticized the dismissal of the attorney general, "who is fighting corruption and impunity."