(Reuters) China and the United States have agreed to roll back tariffs on each others goods in a phase one" trade deal if it is completed officials from both sides said on Thursday sparking division among some advisers to President Donald Trump. The Chinese commerce ministry without laying out a timetable said the two countries had agreed to cancel the tariffs in phases. A U.S. official speaking on condition of anonymity confirmed the rollback would be part of the first phase of a trade agreement that is still being put to paper for Trump and President Xi Jinping to sign. White House spokeswoman Stephanie Grisham told Fox News Channel the United States is very very optimistic" about completing a deal that would defuse a 16-month trade war between the worlds two largest economies. I cannot get ahead of the talks with China but we are very very optimistic that we will reach a deal soon" she said.