Belarusian leader Alexander Lukashenko complained to Russian President Vladimir Putin about increasing pressure from the West and EU sanctions during talks held in Sochi on Friday.
After a dissident's commercial flight between two EU capitals - Athens and Vilnius - was forced to reroute and land in Minsk, Brussels imposed sanctions that penalized state-owned airline Belavia, although it had nothing to do with the incident, Lukashenko said.
Regime critic Roman Protasevich was detained after landing in Minsk, sparking international condemnation.
At the leaders' meeting, Putin criticized an incident in 2013 when the Bolivian president's plane was diverted, without the EU's objections in what he called a US operation.
Lukashenko said he could prove that there had been attempts to destabilize Belarus since the contested elections in August that led to massive protests.
The presidential election was widely regarded as manipulated and hundreds of thousands of people called for Lukashenko's resignation.
Putin emphasized his support for Lukashenko, saying trade between the two countries had increased.
Their meeting came five days after Belarus claimed the plane had to make an emergency landing in Minsk due to a bomb threat, a claim which proved unfounded. During the incident, Belarus sent a fighter jet to accompany the Ryanair flight.
Protasevich, a 26-year-old dissident journalist, and his partner were then taken into custody, prompting a raft of measures by the EU, including restricted access to the bloc's airspace for Belarusian carriers.
On Friday, further information emerged about the forced landing, suggesting that the plane had been diverted before an email alleging the threat had been sent.
"We can see when the email was sent, and we can confirm that the email in question was sent after the plane had been diverted," the Proton email service in Geneva said.
"We have not seen credible evidence that the Belarusian claims are true," the service wrote.
Belarus had claimed that Hamas had sent the threat, a suggestion Hamas repudiated as "absurd" shortly afterwards.
Earlier on Friday, Lithuanian authorities announced that they had questioned the crew and 90% of the passengers who were on board at the time. The investigation of the plane, which remains at the airport in Vilnius, is still ongoing, according to the BNS news agency.
Landing in Russia
Meanwhile it was unclear on Friday whether airlines that were following the EU's recommendation were being blocked from landing in Russia.
Some airlines, such as Air France, reportedly had to cancel flights after alternative routes that avoided Belarus were not approved.
The EU's top diplomat, Josep Borrell, said that he did not know yet if Russian authorities were making the decision case-by-case or had implemented a general rule, and would wait before taking any action.
Kremlin spokesperson Dmitry Peskov spoke of "technical problems" after the EU's decision, but said authorities were working to sort them out.
Later, Lithuania expelled two Belarusian diplomats for activities that were "not compatible with their status," the Foreign Ministry said. Belarus responded by expelling two Lithuanian diplomats.
Looking to the future, the European Commission suggested providing billions in aid to support democratic change in Belarus.
It could make 3 billion euros (3.6 billion dollars) available to Minsk "once Belarus embarks on a democratic transition," the commission said in a press release.
The move should be seen as the bloc's commitment "to support the Belarusian people's wishes for a peaceful democratic transition in the country."