Asked about a $14 billion weapons package for Taiwan, Rubio said it's still being reviewed by the White House.

Last month's summit between Trump and Chinese President Xi Jinping in Beijing led to some concern in Taipei about the U.S. commitment to help the democratically ruled island.

Asked if Trump offered to condition arms sales to Taiwan to placate Xi during their Beijing meeting, Rubio rejected suggestions that the arms sales are being used as leverage in talks with China.

"When the president says it's a great negotiating (tool), what he's really saying is it's because China, as you can imagine, always mentions this. Like this is a top priority for them. They are constantly talking about Taiwan arms sales, but that in no way is what is holding up our decision making or the White House's decision making."