Russia is the biggest economy outside the 153-member club, 18 years after setting out on the path to membership. Its tiny southern neighbour, with which it fought a border war in August 2008, could still thwart its plans because all new members must agree terms with all existing members before they can join.

"For the moment I cannot say whether a deal will be reached or not," Georgian Ambassador Zurab Tchiaberashvili told Reuters. "It depends on the constructive approach from the Russian side.

Among those urging a deal by the end of this year is the United States, Georgia's ally.

WTO chief Pascal Lamy has also said he believed a deal was in sight for the first time.

"We don't feel any pressure," Tchiaberashvili said. "We are speaking about the sovereign right of a member of the WTO to sort out its outstanding issues with a country that wants to become a member of the WTO.

"For us it's essential that we play according to the rules."

Georgian and Russian officials met on Tuesday in Geneva to prepare the technical ground for a potential deal on the thorniest outstanding issue: customs checks on the border between the two former Soviet republics.

Their top negotiators will meet in mid-September, along with Swiss mediators, to try to agree how such a deal might work in practice. Russian trade officials in Geneva were not available for comment.

Tchiaberashvili said any deal would have to include international monitors on two checkpoints -- one in each of the breakaway Georgian regions of Abkhazia and South Ossetia.

He declined to be drawn on the likelihood of an eventual deal but said: "For the moment the rhetoric and the actions by the Russian Federation does not contribute to the constructive and positive outcome of negotiations."

He said at the end of the last round of negotiations in July President Dmitry Medvedev submitted a customs agreement with Abkhazia to Russia's parliament. "In the midst of the negotiations, to do such a thing puts into question whether Russia really wants to do a deal on this issue," he said.

Russia had also disclosed sensitive details of the talks and claimed it could ignore a Georgian veto, he said.

"So for the moment we have a lot of questions concerning the Russian political will to join the WTO."

He said Georgia was acting responsibly and not using its position to wield arbitrary power over Russia.

"Definitely, whatever contributes to the trade facilitation we are happy to see. Russian membership in the WTO will increase trade on the continent so it will benefit everybody.

"There is also the aspect that the more responsibly Russia behaves in the international area and subjects itself to international regulations and rules and international law, the better it is for Georgia."

(Reporting by Tom Miles)