U.S. and allied troops have pushed back Taliban insurgents in a major offensive in Afghanistan but there is still a long way to go, U.S. President Barack Obama said on Saturday. "We knew that this summer was going to be tough fighting ... They (the Taliban) have, I think, been pushed back but we still have a long way to go. We've got to get through elections," he said in a televised interview during his visit to Ghana.He said the United States and its allies would have to evaluate the situation after Afghanistan's Aug. 20 presidential election to see what more they could do. "It may not be on the military side, it may be on the development side," he said. U.S. and British forces are both involved in fierce fighting in the Taliban bastion of Helmand in southern Afghanistan. Obama praised the "extraordinary role" British soldiers had played in Afghanistan and said his heart went out to the families of eight British soldiers killed there in the last few days. Asked whether Washington still needed British forces in Afghanistan now that it was ramping up its forces there, Obama said, "The contribution of the British is critical."