MOSCOW — Belarusian President Alexander Lukashenko met with Russia's Vladimir Putin on Monday for their first encounter since anti-government protests erupted in Belarus a month ago, in a sign that the two leaders have drawn closer amid the crisis after months of strain over bilateral ties.

The cost of Russia’s support for the embattled Lukashenko, however, could be the political and military merger that Belarus has been resisting for two decades.

“These events showed us that we need to stick closer to our older brother,” Lukashenko told Putin in the portion of the closed-door meeting that was shown on state television, referring to the protests.

The Kremlin said in a statement that “the prospects for promoting integration processes within the Union State” — referring to the 1999 union agreement between the two countries — were on the agenda for the Monday meeting, which was held in the Black Sea resort of Sochi.

When Putin and Lukashenko last met in Sochi, in February, relations between the two longtime allies had deteriorated. Lukashenko had again declined to form a unified state, so Moscow had withheld from Minsk the discounted oil it had long sold it.

Lukashenko responded by diversifying Belarus’s oil imports, even buying from the United States.

But with Lukashenko facing the greatest challenge to his 26-year rule amid mass protests calling for his ouster, he has reached out to Putin for help. The two had six phone conversations in August, twice as many as in all of last year. Putin announced in late August that a Russian military contingent is ready to intervene on behalf of Lukashenko “if necessary.”

“For two weeks, the Kremlin watched closely to see whether Lukashenko was determined enough to cling on to power, whether there was a split within the elite, whether the security ­services would betray him,” the Carnegie Moscow Center’s Alexander Baunov wrote in a recent commentary. “Satisfied that Lukashenko was indeed determined enough, and that there was no division, the Kremlin made the decision once and for all to support him.”

“After all, there’s no other visible candidate who would better guarantee the Union State that Russia and Belarus form, or who would keep Belarus the same distance — or further — from the West,” Baunov continued.

There have been demonstrations in Belarus every day since Aug. 9, when the 66-year-old Lukashenko claimed that he won a sixth term as president with more than 80 percent of the vote despite widespread accusations of vote-rigging. Opposition groups and Western governments have rejected the election results.

Putin’s show of support has seemingly emboldened Luka­shenko, who has cracked down on the opposition. Many foreign independent news outlets have been stripped of their accreditation, while members of Russia’s state-owned media have been invited in.

Top opposition activist Maria Kolesnikova was jailed last week and said in a formal complaint released by her attorney that security agents put a bag over her head and drove her to the border with Ukraine in an attempt to expel her from Belarus.

Authorities have also been more aggressive in dispersing demonstrations: The Interior Ministry said Monday that 774 people were detained in protests the day before, including more than 500 in Minsk, the capital.

Constant Internet shutdowns to stymie protests have also crippled Belarus’s budding tech sector, the only part of its economy to post any significant growth in recent years. Last month, chief executives from Belarus’s leading tech companies called on Lukashenko to hold a new election and halt police violence, threatening to take their businesses out of the country. The destruction of that industry could ultimately make Belarus even more reliant on Russian investment.

But Artyom Shraibman of Sense Analytics, a Minsk-based political consultancy, said Lukashenko’s limited options do not necessarily make a deeper union between Russia and Belarus inevitable. For one, such an arrangement isn’t likely to be recognized by protesters and by Western governments that already consider Lukashenko illegitimate and could threaten economic sanctions.

Shraibman expects that Putin could receive other concessions from Lukashenko for his support, such as trading through Russian ports rather than those of the Baltic states.

Lukashenko may not be completely without leverage, either.

“Russia does not have many alternatives in Belarus,” Shraibman said. “If Lukashenko refuses to satisfy some very ambitious demands of Russia, what choice does Russia have? To intervene militarily? To occupy the country? To stop giving Belarus new loans? Well, then Lukashenko will stop paying the old loans.

“This is not as easy as it might seem. Lukashenko’s weakened legitimacy is not a prize for Russia; it’s a problem for Russia,” he said.