WASHINGTON - US Secretary of State Rex Tillerson said on Wednesday the Trump administration is committed to the long-standing "One China" policy as it reviews US policy toward China, but also intends to keep all of its commitments to Taiwan."It is important as we engage with them that we are able to fulfill our commitments to Taiwan, which we have every intention of doing," Tillerson told a congressional committee."The question is, is the One China policy sustainable for the next 50 years? And those are the kind of discussions we're having. They are extremely complex in many regards," he said.