Belarusian leader Alexander Lukashenko landed in Moscow on Friday for talks with Russia's President Vladimir Putin that Minsk said could determine how much longer Russian military forces remain in the ex-Soviet republic north of Ukraine.
Russia's joint war games in Belarus, which are meant to run until Sunday, have added to Western fears that Moscow could launch an attack on Ukraine, which shares borders with both countries.
Russia denies any plan to invade. Both Minsk and Moscow have said the Russian forces - Moscow's biggest deployment in Belarus since the end of the Cold War, according to NATO - will leave when the drills are over.
But Lukashenko's rhetoric has since opened up the possibility that the forces, which are part of a wider Russian buildup to the north, east and south of Ukraine, could actually stay longer.
"Whatever decision we take tomorrow, that's how it will be," Lukashenko was quoted as saying by the BelTa news agency on Thursday.
"It we take a decision, we'll remove (the force) within 24 hours. If we decide a month, they'll stay for a month. The armed forces will stay as long as needed," Lukashenko was quoted as saying.
He also said Moscow and Minsk had agreed Russia would leave ammunition in Belarus and that Minsk could purchase military equipment from Russia, or simply receive it as a "gift".
The military drills have displayed Moscow's tightening grip on Minsk.
For years Lukashenko, a wily political operator in power since 1994, played off East against West for political gain and resisted the idea of hosting a permanent Russian military base.
But since Putin shored him up with political and economic support to help him weather huge opposition protests in 2020 he has shed much of that appearance of autonomy.
Franak Viacorka, an adviser to Belarusian opposition leader Sviatlana Tsikhanouskaya, described Lukashenko as a vassal of Moscow. "We are seeing Lukashenko surrendering Belarusian sovereignty," he wrote on Facebook.
(Reporting by Tom Balmforth; Editing by Mark Trevelyan)
