Democratic frontrunner Hillary Clinton and her allies have begun preparing a playbook to defeat Donald Trump in a general-election match-up.

COMMENT: He's a pouty-lipped liar but there is something about the guy. He's funny, has great one-liners and he's energised.

Mitt Romney is calling for republicans to join together in doing one thing - vote for Cruz and force an open convention.

Fox News has blasted Republican candidate Donald Trump over his "sick obsession" with female anchor Megyn Kelly.

As Donald Trump basked in the glow of victories, he gave a shout-out to embattled campaign manager Corey Lewandowski, positioned at his right hand.

Brazil's Lower House of Congress has launched impeachment proceedings against President Dilma Rousseff after thousands of Brazilians took to the streets.

A secretive group of Republican operatives and conservative leaders convened for more than three hours to discuss ways to unite the right against Donald Trump.

The warning was issued by the London-based Economist Intelligence Unit, which put a Trump presidency in sixth place among the top 10 risks facing the world.

Clinton is likely to become the first major-party female presidential nominee of our times, and happens to be running when women are ruling comedy.

Seeking to preserve his policies from a Republican commander in chief, Obama is poised to be the most active sitting president on the campaign trail in decades.

Donald Trump has warned of riots if he is denied the party's presidential nomination and pulled the plug on a scheduled debate among candidates.

Russian President Vladimir Putin, with his sudden move to withdraw Russian forces from Syria, once more caught international observers by surprise.

COMMENT: With presidential race and border crossings turned into lucrative TV, issues of office solve themselves, writes Jerry Flay.

Here are official and unofficial spokespeople who help fuel the fire for Trump on TV.

Republican front-runner shares a photo of a baseball signed by Ohio legend Pete Rose. But now it turns out that what some thought was an endorsement wasn't.

COMMENT: Trump has turned the entire political world upside down, he's turned it into a sideshow of stylised violence, writes John Dybvig.

Husband of former vice-presidential candidate Sarah Palin hospitalised after a "very serious" snowmobile accident.

Iran's Foreign Minister talks with Murray McCully kicked off with some small talk about Zarif's plane and an offer for Mr McCully to visit Tehran in May.

Germany's Chancellor was not only absent from the election rally for the party she leads - she wasn't invited.

"Fantasy and schoolyard taunts" - The President of the United States says the Republican Party is getting what it asked for.

Ohio governor blames Republican rival for clashes in Chicago and elsewhere between Trump supporters and protesters.

Arnold Schwarzenegger, Tom Selleck and Mr T joined mourners to bid farewell to former US First Lady Nancy Reagan at her funeral on Friday.

Florida Senator Marco Rubio made a bid to try and block Donald Trump from winning the Republican presidential nomination.

COMMENT: The Left and Right are agreed that Trump would demean the world's most prestigious political office.

A promise of something for nothing. A childish insult. And a crowd eating it all up. Sounds familiar.

Moral dilemmas often pit narrow self-interest against the greater good, writes Paul Thomas.

Nixon and Kissinger's diplomacy would now be seen as capitulation, writes Vincent Matthews.

You want to be mayor? Get a wall.

US President has friends in Auckland and his children want to make the trip.

NZ one of six countries in relationship-building tour of Asia-Pacific following the lifting of sanctions on Iran.