Big breakthroughs between Washington and Moscow will have to wait until after the November US elections, with the two sides meanwhile doing “homework” on isues such as missile defence, a top US official said Friday. “This is an important ‘homework’ period in the US-Russia relationship,” Acting Undersecretary for Arms Control and International Security Rose Gottemoeller told reporters and students at a Moscow university. “Now we have to think about the future,” said the veteran Russia expert. “How are we going to cooperate on missile defences?” US plans to deploy a NATO-backed missile defence shield in Europe has strongly bothered Russia, which wants a legally binding agreement saying the system would not be used or aimed against it at any time. Gottemoeller’s remarks came just days after US President Barack Obama was overheard telling his Russian counterpart Dmitry Medvedev that he could be more flexible on the controversial issue once he is re-elected in November.