Four eastern European Union members on Thursday backed the accession of Western Balkan countries to the bloc, saying North Macedonia and Albania should start talks this year.

Visegrad-Four (V4) group premiers from the Czech Republic, Hungary, Poland and Slovakia made the statement at a summit with counterparts from five western Balkan states in Prague.

"The Visegrad-Four group wants to welcome new EU members and it fully endorses the opening of accession talks with North Macedonia and Albania this year," Slovak Prime Minister Peter Pellegrini told reporters.

In a joint statement, the V4 leaders called on the EU to accelerate ongoing accession talks with Montenegro and Serbia.

The V4 also said reforms adopted by Bosnia and Herzegovina and Kosovo would bolster the two countries' hopes of joining the EU.

"The reunification of Europe cannot be complete unless the entire Western Balkans region joins the European integration process," said Czech Prime Minister Andrej Babis, whose country currently presides over the V4.

"The EU enlargement policy is the most efficient tool to support stability, security, democracy, and prosperity in Western Balkans," he added.

"Security in the Balkans also means security in Europe," Babis said.

Polish Prime Minister Mateusz Morawiecki warned that if the EU fails to "come up with an offer for southern European countries or the Western Balkans, countries like Russia, Turkey or China will be very active there."

Albania, Bosnia and Herzegovina, Montenegro, North Macedonia and Serbia attended the Prague summit.

"If the EU hadn't slept on accepting North Macedonia and Serbia as members, there would be fewer illegal migrants in Europe," Hungary's outspoken Prime Minister Viktor Orban said at the meeting.

V4 countries have clashed with western EU members over migration policy, among other issues, with several of them refusing to accept migrants and asylum seekers during Europe's 2015 migrant crisis.

A former Serbian province, Kosovo only sent its ambassador to the summit after Czech President Milos Zeman accused its leaders of being "war criminals."

The pro-Russian, pro-Chinese Zeman also said he would ask the Czech government to reconsider its 2008 recognition of Kosovo's sovereignty.

PM Babis has ruled this out, saying there was "no reason for the Czech government to change its standpoint."