GENEVA, Oct 4 (Reuters) - New sanctions by G7 countries on Russia will target its oil and products in three phases, Ben Harris, assistant secretary for economic policy at the U.S. Treasury, told the Argus European Crude Conference in Geneva on Tuesday.

Harris said sanctions due to take effect on Dec. 5 will target Russian crude oil, while later ones will focus on diesel and finally on lower value products such as naphtha. (Reporting By Julia Payne; Writing by Noah Browning; Editing by Andrew Heavens)