The United States is encouraged by the momentum that has entered Russia's 17-year-old bid to join the World Trade Organization, a U.S. official said on Tuesday, according to Reuters. The comments suggest Washington is still keen to get Russia into the body that referees global trade as soon as practicable, despite a series of issues dogging bilateral trade ties. "There's momentum in the process, a lot of energy on the part of Russia, a lot of interest on the part of many members," the official, who asked not be identified, told Reuters after a meeting of Russia's WTO accession working party. U.S. President Barack Obama and Russian President Dmitry Medvedev said in June they had instructed their negotiators to resolve technical issues by the end of September to clear the way for Russia to join the WTO. That deadline is certain to be missed but Washington and Moscow are keen to push ahead in the coming months. The accession working party will meet again in the week of Oct. 25 and Russia is holding a series of bilateral consultations with a dozen WTO members this week. The U.S. official said a lot of technical work still remained to be done on Russia's accession bid. The main practical difficulty now in the negotiations is Russia's membership of the customs union that it has set up with Belarus and Kazakhstan, which would make it difficult for Russia to join the WTO without the other two, although their own accession processes are much less advanced. The WTO's 153 members want to know how Russia's participation in the customs union will affect the commitments it makes to opening up its markets to WTO members. Russia's chief WTO negotiator, Maxim Medvedkov, said Moscow was working with the United States to tackle its concerns about Russia's intellectual property regime and with the European Union about Russian export duties on timber.