Mijalkov, a first cousin of conservative former Prime Minister Nikola Gruevski, is accused of masterminding phone taps on more than 20,000 people, including politicians, judges and journalists between 2006-2016.
The President of Serbia has compared the distribution of the coronavirus vaccine in Europe to the sinking of the Titanic - saying the rich are being saved while the poor of the Balkans are being left to drown.
While the whole region was waiting to get at least some vaccines from the COVAX scheme, a plane from China landed in Belgrade with a million doses on board.
The Dayton Agreement was a peace deal signed 25 years ago to end the 1992-1995 Bosnian War.
The diplomatic incident between Montenegro and Serbia adds to already tense relations between the Balkan states that were part of the same country until an independence referendum in 2006.
Montenegro's opposition is on the cusp on forging a historic coalition, ending nearly 30 years of rule by the country's Democratic Socialists. There is a lot on the agenda to turn the country around.
Serbian President Aleksandar Vucic and Kosovo’s Prime Minister Avdullah Hoti both described the deal, a diplomatic boost for Donald Trump, as a "huge step forward".