Russia has vetoed a United Nations resolution on proposed security arrangements for Cyprus should the islanders vote for reunification.
Russia was the only opponent in the Security Council
Russia's Deputy Ambassador to the UN, Gennady Gatilov, said his country saw the resolution as an attempt to influence Saturday's twin referendums.
"The [referendums] must take place freely, without any interference, or pressure from outside," he said.
The other 14 members of the Security Council voted in favour of the text.
UN Secretary General Kofi Annan had urged the Council to adopt the resolution, which outlined plans for a new peacekeeping operation and an arms embargo.
He is presenting his own version of a peace plan to both Greek Cypriots and Turkish Cypriots after political leaders of the two sides failed to agree a compromise.
However, many Council members raised questions about why the resolution, sponsored by the US and the UK, was needed before this week's referendums.
Several objected to the pressure on the Council to act so quickly.
Thursday is the last day of campaigning for the separate Greek and Turkish Cypriot votes.
If both sides support Mr Annan's proposals, a united Cyprus will join the European Union on 1 May.
If either side rejects the plan, membership will in effect apply only for the Greek Cypriots.
'No better plan'
Earlier, the senior EU official supervising the imminent expansion of the Union, Gunter Verheugen, had said the government in the Greek part of Cyprus had cheated the EU by pretending to support the unification plan while in reality campaigning against it.
Mr Verheugen said the government "had taken him for a ride" and he directly criticised the Greek Cypriot leader, Tassos Papadopoulos.
The Greek Cypriot leadership is calling for a "no" vote on Sunday, while the Turkish Cypriot north is expected to vote "yes".
Mr Verheugen attacked what he called the "surprising and troubling" attitude of the Greek Cypriot government.
"I did everything to create the conditions allowing Greek Cypriots to accept
the UN plan - apparently in vain," Mr Verheugen told the European Parliament.
"There is no better possible plan."
He called on the Greek Cypriot leader to respect his part of the deal.
"Mr Papadopoulos has called back into question the federal
solution, as set out by the UN, the EU and himself on the basis of
equal treatment of the two communities," he said.
"We accepted at the request of the Greek Cypriots that the
solution should not constitute a prerequisite for Cyprus' (EU)
accession... but the Cypriot government had to do everything
possible to find a solution to the conflict.
"We had a clear agreement on this point. Mr Papadopoulos must
respect his part of the deal," he said.
EU officials also believe the Greek Cypriot public is being presented with biased information about the peace plan.
"The very least we could expect is a
fair and balanced information campaign about the objective
and the content of this plan," Mr Verheugen said.
Polls suggest that Greek Cypriots will reject the plan over anger that not all refugees will get their old homes back and that Turkish troops will be able to stay on the island indefinitely.
The island was divided in 1974, when Turkey invaded the northern third in response to a Greek Cypriot coup.