US Republican presidential frontrunner Donald Trump says he is planning to spend $2m a week on campaign advertising. Mr Trump said he would bring out “substantial” adverts in Iowa, New Hampshire and South Carolina ahead of primary elections in February. “I’ll be spending a minimum of $2m a week and perhaps substantially more,” Mr Trump said in a video broadcast on CNN.”I’m going to be doing big ads in Iowa, New Hampshire, South Carolina, and they are going to be very substantial.” Mr Trump, a property tycoon, has previously said that he is funding his campaign himself and wouldn’t be in the pocket of lobbyists or powerful corporate entities. Meanwhile, former New York Governor George Pataki is reported to have said he is quitting the Republican race. Correspondents say he has failed to make any impact in the polls.