House of Representatives speaker Paul Ryan said of Donald Trump: “I think conservatives want to know: does he share our values and our principles.” Photograph: Jonathan Ernst/Reuters

Paul Ryan, the Republican speaker of the House of Representatives, has said that he is “not ready” to endorse Donald Trump as his party’s presidentia(...)

US secretary of state John Kerry in Vienna with foreign ministers Philip Hammond of the UK, Sergei Lavrov of Russia, Javad Zarif of Iran, Frank- Walter Steinmeier of Germany, Laurent Fabius of France and EU envoy Catherine Ashton and Chinese foreign minister Wang Yi. Photograph: Joe Klamar/Reuters

Iran and six world powers failed on Monday for a second time this year to resolve their 12-year dispute over Tehran’s nuclear ambitions, and gave them(...)

An Islamic State militant uses announces to residents of Taqba city that Tabqa air base has fallen to his group. Photograph: Reuters

Senior Republicans yesterday called for expanded air strikes against Islamic State militants in Iraq and for the first time in Syria, to destroy th(...)

A bill currently being debated by the US Senate would compel internet sellers making over $1 million a year to pay a sales tax for every(...)