‘If Obama vetoes a resolution of disapproval, it will take 34 senators to override his veto and block the agreement. That means opponents have to find an unlikely 11 more Democrats. Photograph:  REUTERS

It would not be unusual for members of the US Congress to vote against an international agreement, denouncing it with rhetorical flourishes as appalli(...)

Demonstrators hold signs during a protest in Sao Paulo, Brazil, during a protest in Sao Paulo, Brazil, on Sunday. Nationwide street protests against Brazilian president Dilma Rousseff are keeping pressure on the government. Photograph: Patricia Monteiro/Bloomberg 1:27

Hundreds of thousands of demonstrators returned to the streets in dozens of Brazilian cities on Sunday to call for the impeachment of president Dilma(...)

Jeb Bush has declined to rule out the US resuming the use of torture – with the Republican presidential hopeful saying brutal questioning methods might be justifiable. Photograph: Bloomberg

Jeb Bush has declined to rule out the US resuming the use of torture – with the Republican presidential hopeful saying brutal questioning methods migh(...)

The furious reaction from the American right and vested interest groups to President Barack Obama’s dramatic announcement of his Clean Power Plan last(...)

Democratic Senator Chuck Schumer, who has said he will oppose the nuclear deal between Iran and world powers. Photograph: Andrew Harrer/Bloomberg

US president Barack Obama’s hopes of preserving the nuclear deal between Iran and world powers have been dealt a setback with the announcement by C(...)

Wisconsin Governor Scott Walker  listens as Donald Trump speaks during the Republican presidential debate. Photograph: AFP/Getty Images 0:36

Donald Trump dominated the first Republican presidential debate, where the property mogul was the literal and figurative centre of the action. Trump d(...)

John Kerry: “The fact is that Iran now has extensive experience with nuclear fuel cycle technology. We can’t bomb that knowledge away.” Photograph: Gary Cameron/Reuters

US secretary of state John Kerry on Thursday mounted a furious counterattack against critics of the Iran nuclear deal, telling sceptics it would be fa(...)

Republican presidential contender and businessman Donald Trump. Photograph: Daniel Acker/Bloomberg

Republican presidential contender Donald Trump attacked Arizona senator John McCain’s war record on Saturday, saying the former prisoner in North Viet(...)

 President Barack Obama: stressed that there was no alternative to the deal. Photograph: Getty Images

The tough negotiations leading to a nuclear deal with Iran may have concluded in Vienna, but the hard work on selling the agreement to sceptical Repub(...)

President Barack Obama, with Vice President Joe Biden, at a press conference in response to the Iran nuclear deal. Photograph; Andrew Harnik/Getty Images

US president Barack Obama faces stormy weeks ahead as he must convince fellow Democrats and Republicans at home and disgruntled allies in the Middle E(...)