This comes after the country's electoral authorities had declared incumbent president Juan Orlando Hernandez the winner of the 2017 presidential elections on Sunday, three weeks after the vote was originally held.
"The only possible way for the victor to be the people of Honduras is a new call for general elections, within the framework of the strictest respect for the rule of law," OAS Secretary General Luis Almagro said in a press release.
The OAS observation mission to Honduras found several different issues with the electoral process, including "deliberate human intrusions in the computer system, intentional elimination of digital traces," and "pouches of votes open or lacking votes."
Those and other factors made determining a winner "impossible," the press release said.
The OAS is a regional non-partisan organization comprising 35 countries.
Supreme Electoral Tribunal president David Matamoros said the ruling National Party candidate won with 42.9% of the votes, over 1.5% more than his main challenger, Salvador Nasralla, who came in second with 41.24%.
Clashes broke out Sunday night as Matamoros announced the winner.
Prior to the announcement, Almagro had tweeted that there were still "serious doubts" regarding the election results. The tweet said this was based on information gathered by the international entity's mission of observers on the ground.
Matamoros said all the ballots had been counted and irregularities resolved. The tribunal tweeted paraphrased lines from the OAS' preliminary report
, which suggested that the observers findings were in line with the Tribunal's.
"Mission of Electoral Observers of the @OE_oficial on their final report of the #HondurasElections2017, ratified that 'there's certainty that the result expressed by the # TSE (Supreme Electoral Court) and its bills are the same ones that the political parties got, and the same ones of the mission,' the tweet said.
The preliminary report, which the tweet cites, suggests that "this review, the (OAS) can conclude that in almost all the proceedings there is a coincidence between the officials and the (proceedings) obtained by the parties."
Highly disputed contest
The election, which took place on November 26, has been highly scrutinized by many in Honduras and abroad. Irregularities in the processing of the votes prompted days of unrest
that claimed at least 11 lives, and forced the government to impose a nightly curfew in an attempt to control protests.
During a video message posted to Facebook
, Nasralla called the announcement a "desperate measure" and said he "rejected the fraud." The defeated challenger posted the message from an airport in the United States and he was scheduled to meet with Almagro in Washington DC on Monday.
Ballots from 1,000 voting precincts showed irregularities after the electoral commission's voting system shut down while the count was ongoing. Nasralla alleged the shutdown was part of an attempt by the government to manipulate the vote.
Thousands of his supporters took to the street in Tegucigalpa after the botched count in what was a largely peaceful demonstration. Many of them, demanding a recount, told CNN that they marched because they felt cheated, not because of their ideology.