The United States on Saturday said it was working hard to get back to work with Pakistan. “This relationship is complicated. But it’s also essential to both the United States and Pakistan. We are working very hard to keep open channels and to get back to work together,” State Department spokeswoman Victoria Nuland told reporters. The US officials have been in constant contact with their counterparts in Pakistan, the latest being the meeting between the US ambassador to Pakistan, Cameron Munter with Foreign Minister Hina Rabbani Khar.“We are continuing our intensive engagement. Obviously we are both trying to roll up our sleeves and get back to work together,” Nuland said. She said there was no reason to believe that the Dubai visit of President Asif Ali Zardari had anything to do with other than his health issue.