"Into Nato" posters can be seen on the streets of the Georgian capital
A series of Nato military exercises has begun in Georgia, amid angry condemnation from Russia.
Soldiers from 18 countries are taking part in the drills at a Georgian army base close to the capital, Tbilisi.
Russia, which fought a war against Georgia last year, has condemned the exercises, which President Dmitry Medvedev called "an overt provocation".
On Tuesday Georgia put down a mutiny by soldiers, and claimed it had uncovered a Russian-backed coup plot.
Relations between Nato and Russia were supposed to have been on the mend after last year's war in Georgia, but have now taken a dramatic turn for the worse, the BBC's Rupert Wingfield-Hayes in Moscow says.
Russia said on Wednesday that it was expelling two Canadian diplomats working for Nato's Moscow office in response to what it terms an "unfriendly act" by the military alliance.
Last week Nato expelled two Russian envoys from its headquarters in Brussels, reportedly due to spying.
More than 1,000 soldiers will take part in the Nato exercises over a period of more than three weeks.
World affairs correspondent, BBC News website
The best hope for an improvement in Nato-Russia ties lies in talks between Washington and Moscow about nuclear weapons. The two sides have set themselves a deadline of December to reach an agreement.
If they do agree that will be an up. But equally there will be downs in future as well.
The basic relationship has not been worked out. There is suspicion among Nato members about the authoritarian nature of the Russian government and its determination to exercise influence over its near neighbours.
And there is suspicion in Moscow that Nato would like Russia to return to the chaotic days of the 1990s, when Russia was passive and compliant.
They are taking place close to areas where Russian troops are stationed in Georgia's breakaway region of South Ossetia.
Georgia's defence ministry said Nato would spend the next few days setting up a staff headquarters at the Vaziani base outside the capital Tbilisi.
The first exercise, running until 19 May, is described as a "command post" exercise focusing on co-ordinating Nato procedures in a crisis-response situation.
Then a second, larger, exercise, based on peacekeeping training, will run till 3 June.
Nato has denied the exercises are aimed at Russia or the breakaway regions of South Ossetia and Abkhazia.
"This issue has been totally misused, I think, by all parties. Georgia is not the object of this exercise, Georgia is the host of this exercise like Armenia was the year before," Nato spokesman James Appathurai told BBC World Service.
"The Russians can portray it the way they want... They're not the only ones to misuse this exercise for political purposes.
"I can tell you the secretary-general has spoken to the leadership in Georgia to express his concern that they also are misusing this exercise for political purposes."
Armenia, Kazakhstan, Serbia and Moldova - Russian allies which had been invited by Nato to participate in the Georgian manoeuvres - have all pulled out.
Nato has promised eventual membership to Georgia, but has given it no target date for entry. Russia is vehemently opposed to Georgian membership.
The mutiny on Tuesday in Georgia is likely to reinforce in the minds of many Nato members that now is not the time to commit the alliance to the defence of such an unstable country, says the BBC's world affairs correspondent Paul Reynolds.
The rebellion erupted on Tuesday morning, when soldiers at a tank battalion began disobeying orders, Georgian officials said.
"The plan was to stage a large-scale mutiny in Tbilisi and to take steps against the sovereignty of Georgia and the Georgian government's European and Euro-Atlantic integration," said President Mikhail Saakashvili.
The interior ministry had earlier said it was part of a Russian-linked coup attempt to kill the president - an allegation described by Russia's envoy to Nato as "mad".