"What's left - there is no complexity in it," Fernando Valenzuela told Reuters this week.

"If there is will on the Russian side to go for the membership -- and of course that means also doing the effort that has to be done -- then we think that it is a process that could go relatively fast.

"This could be done in one year," he said.

Russia's plans to join the WTO, running over 16 years, were suspended last year when Prime Minister Vladimir Putin said Moscow would first create a customs union with neighbors Kazakhstan and Belarus and the three would join the WTO together.

Analysts struggled to explain Putin's move, which came at a time when Russia was closer to joining the WTO than ever. Some saw in it frustration at the slow pace of talks, or Moscow's unwillingness to open its markets at the peak of crisis.

The WTO, the EU and the United States said the move for the three states to join together would be unprecedented and very complicated.

The creation of the customs union itself proved to be more complicated than anticipated and the three countries have postponed its creation from the planned launch date of July 1.

On Tuesday, Russia said it would resume unilateral talks to join the WTO next month.

"We have nothing against the Customs Union," Valenzuela said. "Simply, the process of acceding to the WTO -- if you try to accede as a customs union of these countries -- that multiplies the complexity and the difficulty extremely."

Russia remains the largest economy still outside the 153-member body.

"There is an overall understanding that the process should be sped up," Galina Martinkevich, deputy director of the foreign economic activity analysis and regulation department at the Russian economic ministry.