Montenegro is set to approve accession to Nato on Friday in the face of Russian disapproval.
The country’s parliament is expected to ratify the decision to join the Western military alliance later.
But the move is controversial within Montenegro itself and has angered Moscow, which has banned Montenegrin wine imports, citing sanitary failings.
Montenegro’s Prime Minister Dusko Markovic has dismissed the decision as politically motivated.
A fifth of all wine exports go to Russia, and the ban will have significant impact on sales.
“It is clear that the decision is in the context of Nato membership,” Mr Markovic said.
Montenegro was granted a membership action plan by Nato in 2009, a decade after the alliance subjected the state to a three-month bombing campaign during the Kosovo War.
Nato membership remains highly controversial in the small Balkan country, which became independent in 2006.
Serbia and Montenegro – both bombed by Nato planes – were originally one country after the break-up of Yugoslavia.