State Department Spokesman Sean McCormack said there is a limit to what the West can do to pressure the longtime Zimbabwean leader from office.
"This isn't a case of somebody driving the economy into a ditch; it's over a cliff. So, and again this comes back to the situation with Robert Mugabe," McCormack said. "He has destroyed the political system in Zimbabwe. He has destroyed the economy. He has created a humanitarian crisis in that country."
McCormack also said closing Zimbabwe's borders to force a change in leadership might have broader consequences.
"I'm not sure that closing a border is necessarily the right thing to do if you have people that are fleeing a disastrous situation, or are fleeing for their lives for fear of political oppression. This is a political question. The fact of the matter is that Robert Mugabe and those who are around him are still there in part because they still have political support, or at the very least countries not come out and spoken out against Robert Mugabe and those around them," he said.