As American VP heads to Ankara to push for ceasefire, Turkish leader vows to continue offensive in Syria until Kurdish fighters 'lay down their arms'

Criticism of Istanbul grows amid fierce clashes in northern Syria but Erdogan dismisses US proposal to broker a ceasefire, saying sanctions wont halt operation

Vice president says Trump spoke with Erdogan and asked him to to 'stop the invasion;' US is 'simply not going to tolerate Turkey's invasion of Syria any longer'

Democrats demand documents from administration officials, including vice president, as Trump disparages investigation, refuses to cooperate

US vice president, a key intermediary between White House and Ukraine, has until now rarely been drawn into Trump controversies

US president facing competing urges of keeping up pressure on Tehran to negotiate while deterring any further Iranian attacks and avoiding another Middle East war

Memorials for victims of worst terror attack in US history held at Ground Zero, other crash sites and in Jerusalem

US vice president says Washington 'fully supports Jerusalem as tensions in Middle East skyrocket

President says he is 'very happy' with his vice president ahead of next year's campaign to be reelected for a second term

Countdown at Johnson Space Center in Houston marks exact moment Neil Armstrong first stepped onto lunar surface, as celebrations across US held to commemorate historic achievement