Updated

Serbia's defense minister says that the country is expecting Russian President Vladimir Putin's approval for the delivery of fighter jets, which could worsen tensions with neighboring states.

Defense Minister Zoran Djordjevic told the Blic daily on Sunday that Putin's signature on the delivery of four MiG-29s is only a formality and that "they will be arriving for sure."

Serbian media have said that the delivery will be timed to the April 2 presidential election to boost the chances of current populist Serbian Prime Minister Aleksandar Vucic, who is now vying for the presidency.

The delivery of the MiGs, including another eight being negotiated with Belarus, could further increase tensions in the western Balkans where former Yugoslav republics have been engaged in a war of words over a number of issues.