China has to go through the same process and hurdles in joining TPP that we went through and we went through a lot of hurdles with such a diverse group already in the membership including, as someone has pointed out, Vietnam, which is an even more tightly controlled economy. I think China understands well the kind of commitment it's going to have to make if it wants to join the TPP.
On February 4th, 2014. See this statement in context.