Frontrunners push ahead in race for the White House

US Republican presidential front-runner Donald Trump has called for a "one-on-one" battle with Ted Cruz, urging other rivals to quit the nomination race.

Mr Cruz also suggested it was time for other hopefuls, like Marco Rubio and John Kasich, to step aside.

In the Democratic race, Bernie Sanders took two states - but Hillary Clinton maintained her frontrunner status after a big victory in Louisiana.

Barbara Plett-Usher reports.