The EU suspended most sanctions against Belarus Thursday, citing "improving relations" after authoritarian President Alexander Lukashenko released all remaining political prisoners, a statement said.

"This decision was taken in response to the release of all Belarusian political prisoners on 22 August and in the context of improving EU-Belarus relations," the statement said.

Belarus, which holds a presidential election on Sunday, is a Soviet-style state sandwiched between the European Union and Russia.

Authoritarian President Alexander Lukashenko has ruled the country since 1994 and looks set to win a fifth term.

Once described by the U.S. as presiding over Europe's "last true remaining dictatorship", President Alexander Lukashenko has kept Belarus in international isolation for more than two decades.

Known for his folksy charisma and eccentric style, the mustachioed leader, however, seems to have recently edged his nation of 9.5 million in from the cold, balancing off long-standing ally Russia and the West over the crisis in neighboring Ukraine.

Belarus holds an election Sunday that is likely to see authoritarian President Alexander Lukashenko claim a fifth term, with the EU possibly lifting sanctions against him if the polls take place without incident.

Lukashenko, 61, a swaggering former collective farm director once called Europe's last dictator by Washington, has led the landlocked eastern European country closely allied to Russia since 1994.

Progress has been made on some contentious issues in the peace process, the foreign ministers of Germany, Russia, Ukraine and France said after holding talks in Berlin on Saturday to prepare for a summit in Paris on October 2.

Germany's top diplomat, Frank-Walter Steinmeier, said the meeting had been "less confrontational" than previous ones and that the warring sides were now "very close" to an agreement on withdrawing heavy weapons from the frontline.

Belarus strongman Alexander Lukashenko has released six opposition leaders, including a former presidential rival, less than two months before presidential elections in a move hailed Sunday by the European Union.

A pardon for the six was revealed in a brief statement on Saturday evening. Among the freed opponents was Mikola Statkevich, a former presidential candidate imprisoned since 2010, much of which he spent in solitary confinement.

Belarus strongman Alexander Lukashenko has released from jail six opposition leaders -- considered the last political prisoners in the ex-Soviet state -- less than two months before the next presidential poll, the presidency announced Saturday.

A pardon for the six was revealed in a brief statement. Among the freed opponents is Mikola Statkevich, a former presidential candidate imprisoned since 2010.

Armenia and Belarus are holding up agreement on a joint declaration at the EU-Eastern Partnership summit over references to Russia's annexation of Crimea last year, diplomatic sources said Thursday.

EU leaders are meeting in the Latvian capital Riga with their counterparts from Armenia, Azerbaijan, Belarus, Georgia, Moldova and Ukraine, aiming to cement ties with the former Soviet states but without closing the door on Russia.

U.S. Secretary of State John Kerry on Wednesday warned Russia that now was a critical time to implement a fragile peace deal to end the fighting in Ukraine, after his talks with President Vladimir Putin raised hopes of a slackening in tensions.

Kerry said there was an "enormous moment of opportunity" to bring to an end over a year of fighting in eastern Ukraine between government forces and pro-Russia separatists which has dragged relations between Moscow and the West to a new post-Cold War low.

Belarus faced harsh criticism Monday at a U.N. review of its rights record, with diplomats decrying an "atmosphere of intimidation" and urging the country to ensure free and fair elections.

Gathered at the U.N. Human Rights Council in Geneva, diplomats called on Belarus, which rights groups have dubbed Europe's last dictatorship, to release all political prisoners and to halt executions.