TOKYO (REUTERS) - Japan should push back if President-elect Donald Trump bases trade and other economic policy on "wrong economics", an adviser to Prime Minister Shinzo Abe told Reuters in an unusually direct expression of concern about potential protectionism.

Mr Koichi Hamada, emeritus professor of economics at Yale University and Cabinet adviser, also said Mr Abe could relax his timetable for balancing the budget in the next four years and should be ready to further delay a planned sales tax hike to ensure economic growth.

Threats by Mr Trump, who takes office on Friday (Jan 20), to impose a"border tax" on imports and take other protectionist measures have raised uncertainties about global trade.

"There is some danger if he bases his decisions on wrong economics without listening to good advisers, and if he thinks that he could manage national economic matters as he does his real-estate company," Mr Hamada said in an interview on Thursday (Jan 19).