President Donald Trump on Saturday invited Philippines president Rodrigo Duterte to the White House.Duterte has been criticized following an aggressive crackdown on drug users and dealers in the South-east Asian country, which human rights groups have said included the use of death squads.Trump had praised Duterte's hardline stance on the campaign trail, after the Obama administration had condemned it.Trump said the two countries are "now heading in a very positive direction," according to a White House readout of the call.The two presidents discussed regional security threats such as North Korea.