The comments address fears of election meddling after an effort to disqualify the front-runner's party ahead of the runoff vote.

"I reiterate the commitment to promote an orderly, transparent and efficient transition process," Giammattei said in an address to the nation.

Bernardo Arevalo, a reformist candidate running on an anti-corruption message, leads former first lady Sandra Torres by a large margin in polls ahead of Sunday's runoff.

Arevalo's surprise second-place finish in June's first round vote provoked calls for recounts by opponents.

A prosecutor then persuaded a court to suspend Arevalo's party, threatening to sideline his bid. Guatemala's top court later reversed the ban.

In an interview published on Monday with online news site El Faro, Arevalo said he expected efforts to dispute his potential victory "from different sectors."

"I have no doubt that between Aug. 20 and (inauguration day) Jan. 14, if we win the election, there will be a good number of attempts to prevent it from happening," Arevalo said.

Giammattei, a conservative, said he would not stay in office "one minute longer" than Jan. 14, the scheduled day to hand over power to the incoming elected government.

Earlier this month, Giammattei met with the Organization of American States chief Luis Almagro and expressed his commitment to ensuring peaceful elections, he said at the time in a post on social media platform X.

(Reporting by Sofia Menchu; Writing by Brendan O'Boyle and Sonali Paul)

By Sofia Menchu