Belarusian Foreign Minister Uladzimer Makey starts a two-day visit in Moscow on June 17 focusing on the status of Russian citizen Sofia Sapega, the girlfriend of the detained Belarusian opposition activist Raman Pratasevich.
Russia says Makey was invited to Moscow by Foreign Minister Sergei Lavrov to discuss the situation with Sapega, who is being held in pretrial detention.
Lavrov and Makey are scheduled to discuss her case on June 18.
Belarusian authorities on May 23 pulled Sapega and Pratasevich from a civilian airliner en route from Athens to Vilnius after a Belarusian fighter jet diverted the flight and forced it to land in Minsk.
The diversion of the Ryanair flight by the Belarusian warplane has been condemned internationally as a state hijacking and has prompted Western sanctions against Belarus.
But a Belarusian court on June 14 rejected Sapega's appeal to be released, ruling that her arrest was legal under Belarusian law.
Crisis In Belarus
Read our coverage as Belarusians continue to demand the resignation of Alyaksandr Lukashenka amid a brutal crackdown on protesters. The West refuses to recognize him as the country's legitimate leader after an August 9 election considered fraudulent.
Sapega's lawyer, Alyaksandr Filanovich, said criminal charges had been filed against her. But he has not elaborated, saying he is under a court order not to release details about the case to the public.
The Vyasna human rights center in Minsk says Belarusian authorities have charged Sapega with organizing and preparing activities that violate civil order, organizing "mass disturbances," and inciting hatred.
In an interview with the Kommersant newspaper in late May, Makey said authoritarian ruler Alyaksandr Lukashenka could decide to pardon Sapega or transfer her to Russia to serve a sentence.
The European Union has responded to the diversion of the flight between two EU countries by banning Belarusian airlines from EU airports and airspace. Europe's aviation regulator has also urged other airlines to avoid Belarusian airspace.
Russia has backed Lukashenka in the case.
Russian President Vladimir Putin met with Lukashenka on May 28 -- pushing for further integration between Moscow and Minsk within a so-called union state.
The decades-old bilateral agreement envisages a union with closer political, economic, and security ties between Russia and Belarus.