WASHINGTON: Republican presidential candidate Donald Trump has announced Indiana state's governor Mike Pence as his vice presidential running mate.

Trump's December 2015 announcement, which had called for a ban on Muslims, leaves everyone wondering how Pence will defend his benefactor's policies now as his second-in-command.

"Calls to ban Muslims from entering the US are offensive and unconstitutional", Pence had tweeted on December 8, 2015, the very day Donald Trump had proposed that US should bar all Muslims from entering the country in the wake of the terrorist attack that killed 14 Americans in California on December 2.

Pence, who was elected the 50th Governor of the State of Indiana in 2012 and inaugurated January 14, 2013, earlier represented Indiana’s Sixth Congressional District in Congress.

Donald Trump, the billionaire who is funding his own campaign, was widely criticised for his proposed ban on Muslims and his labeling of Mexicans migrating to the United States as “criminals” and “rapists”,

His Muslim ban proposal was condemned by White House and even some of his Republican colleagues.

Trump, however surprised everyone by securing his party's presidential nomination in May, winning the primary race against 16 other Republican contenders.