Lithuania, Latvia and Estonia imposed travel bans on President Alexander Lukashenko and 29 other Belarusian officials on Monday, signalling impatience with the West’s cautious approach by announcing sanctions without waiting for the rest of the EU.

The three small Baltic states have led calls firm measures against Lukashenko, who is accused by opponents and the West of rigging an Aug. 9 election to prolong his 26-year rule.

The sanctions target officials they accuse of having a role in vote-rigging and in violence against protesters since the election. The inclusion of Lukashenko was a prod to other European countries, so far reluctant to back measures against him personally.

Belarus expressed “sincere disappointment” and signalled it would retaliate in kind to what it called “hasty steps”.

“We said that we need peaceful dialogue and agreement between the regime and society, but we see that the regime is not ready for that,” Lithuanian President Gitanas Nauseda said. “We see that we need to move forward and to show an example to other countries.”

The European Union has been working on a list of individuals in Belarus to target with similar sanctions, expected to exclude Lukashenko. Western countries have mostly been cautious, wary of provoking an intervention from Russia.

“We have said before that Belarus will need to take adequate measures to respond to the initiators of these steps. This will be done,” Anatoly Glaz, spokesman of the Belarusian Foreign Ministry, told RIA news agency.

The three Baltic states are all members of the EU and NATO, and Lithuania and Latvia border Belarus. Lithuania has been hosting Belarusian opposition presidential candidate Sviatlana Tsikhanouskaya, who fled there after the election her supporters say she won.

Tsikhanouskaya will speak to the U.N. Security Council on Friday at Estonia’s invitation, her spokesman said.

Seeking to keep pressure on Lukashenko to step down, Tsikhanouskaya’s team called for students to hold a one-day nationwide boycott of schools and universities on Tuesday to coincide with the start of the new school year.

Three weeks into a mass demonstration movement that has peaked at weekends, tens of thousands of protesters again took to the streets in central Minsk on Sunday.

Lukashenko has shown no sign of bowing to the protests. The former Soviet collective farm boss has denied rigging the election but on Monday referred to Belarusian public life being governed by “a somewhat authoritarian system”.

Lukashenko has threatened to cut off European transit routes across his country in retaliation against any sanctions. Goods from landlocked Belarus account for almost a third of Lithuania’s rail traffic and port volume, and Belarus is also an overland route for European goods bound for Russia.

Belarus is Russia’s closest ally among former Soviet states, and its territory is integral to Moscow’s European defence strategy. President Vladimir Putin has invited Lukashenko to Moscow, a sign of Kremlin support, and the two countries’ foreign ministers will hold talks on Wednesday in Moscow.

Last week, the Kremlin announced it had set up a reserve force able to intervene in Belarus, though Kremlin spokesman Dmitry Peskov repeated on Monday that Moscow still sees no need for action.

During the three weeks of protests, Lukashenko has lost the support of a range of public figures, from actors to sportsmen.

On Monday, the Catholic Church in Belarus, which has criticised the harsh treatment of protesters by the security forces, said its head, Tadeush Kondrusevich, had been barred from re-entering the country after a trip to Poland. The border guards declined to comment.

Reuters