The EU on Tuesday called for the swift formation of Serbia's new parliament and government following the certification of early parliamentary election results, stressing the need for an orderly transition of power.

In a joint statement, EU foreign policy chief Kaja Kallas and Commissioner for Enlargement Marta Kos said the certification of the results should pave the way for a smooth transition and the formation of new institutions without delay.

"The Parliament and government to be formed without delay in order to begin addressing the key challenges Serbia is facing," the statement said.

Citing preliminary findings by an international election observation mission, the EU acknowledged generally efficient preparations and positive assessments of voting procedures at most polling stations.

However, the observers also raised concerns about advantages enjoyed by the ruling party, including alleged misuse of state resources, media bias, voter intimidation and pressure on candidates and civil society. They also reported disruptions to campaign activities and incidents of physical violence.

"The EU remains ready to work closely with the incoming Serbian government on the fundamentals of the EU accession process," the statement said, referring to democratic standards, judicial independence and fundamental rights.

"The EU stands ready to offer support with the reforms and to turn these into opportunities for the people of Serbia," it added.

Serbia's student-backed opposition won 52.71% of the vote in the Oct. 25 snap parliamentary elections, securing 140 seats in the 250-member National Assembly, according to the election results provided.

President Aleksandar Vucic's "United Serbia" received 39.17% of the vote, with a projected 104 seats.