The 2016 Republican candidates sparred at length over foreign policy - especially how to address the rise of the self-proclaimed "Islamic State" (IS) - on stage in Las Vegas. Tuesday's debate among the nine leading candidates comes just seven weeks before voters in Iowa cast the first ballots in the Republican primaries.

Real estate developer Donald Trump defended his proposed ban on Muslims entering the US, describing security and "not religion" as being at stake in the suggestion.

Former Florida Governor Jeb Bush countered by slamming Trump as a "chaos candidate" and defending comments in which he described the Republican frontrunner as "unhinged." Fellow opponent Marco Rubio dismissed Trump's suggestion as never going to happen, pointing to legal and logistical challenges.

Nobel Prize winner Malala Yousafzai also condemned Donald Trump's views on Muslims on Tuesday, commenting that it's "tragic that you hear these comments which are full of hatred, full of this ideology of being discriminative towards others."

Each of the candidates outlined how they would target IS in a bid to limit security threats stemming from the terror group - with Rubio and Senator Ted Cruz clashing over their policies on counterterrorism surveillance by the government.

Candidates point to professional experience

The primetime event also featured New Jersey Governor Chris Christie, who said his time as a federal prosecutor gives him the background other contenders lack to deal with problems faced by the president.

Former Hewlett-Packard CEO Carly Fiorina also highlighted her experience as an executive in addressing policy issues, saying she would tap Silicon Valley to help counteract the influence of "Islamic State" online.

Ohio Governor John Kasich warned those on stage that Republican presidents have always had to win his state in order to take the presidency. He said his constituents want reform paired with security.

Lengthy exchanges on immigration policy - a key issue for Republicans in 2016 - highlighted differences between the candidates.

Marco Rubio and Ted Cruz continue to clash over immigration, with the two senators repeating attacks they have been making on the campaign trail. Cruz criticized Rubio for his work on a 2013 Senate bill that provided a path to citizenship to immigrants in the country illegally.

sm/gsw (AP, AFP)