Orlando shooting: Donald Trump calls for Barack Obama's resignation

Republican White House contender Donald Trump claimed that Afghan-origin gunman Omar Mateen shouted "Allah hu Akbar!" as he slaughtered clubgoers.

Washington: Republican White House contender Donald Trump has called on President Barack Obama to resign for not using the term "radical Islamic terrorism" to describe the gay club massacre even as his Democratic rival Hillary Clinton backed redoubling of efforts to defeat terror groups.

"Is President Obama going to finally mention the words radical Islamic terrorism? If he doesn't he should immediately resign in disgrace!" Trump said in a series of tweets as he slammed the US President for not blaming radical Islam for the terror attack by the lone Afghan-origin gunman Omar Mateen at a public bar in Orlando that claimed at least 50 lives.

In another tweet, Trump claimed that Mateen shouted "Allah hu Akbar!" as he slaughtered clubgoers.

The police, however, is yet to corroborate this claim of Trump.

The 69-year-old presumptive Republican presidential nominee also stated that a second man was arrested in Los Angeles with rifles near the Gay parade.

The police, however, has so far ruled out any link between the incident in Los Angeles and the Orlando shooting, which is the deadliest mass shooting in American history.

In a separate statement, Trump also asked Hillary Clinton, the presumptive Democratic presidential nominee to get out of the race.

"In his remarks today, President Obama disgracefully refused to even say the words 'Radical Islam'. For that reason alone, he should step down. If Hillary Clinton, after this attack, still cannot say the two words 'Radical Islam' she should get out of this race for the Presidency," Trump demanded.

"Last night our nation was attacked by a radical Islamic terrorist. It was the worst terrorist attack on our soil since 9/11 and the second of its kind in 6 months. My deepest sympathy and support goes out to the victims, the wounded and their families," he said.

"If we do not get tough and smart real fast, we are not going to have a country anymore. Because our leaders are weak, I said this was going to happen and it is only going to get worse. I am trying to save lives and prevent the next terrorist attack. We can't afford to be politically correct anymore," Trump said.

Meanwhile, Hillary, 68, described the Orlando mass shooting as an act of terror and called for redoubling of efforts to defeat international terror groups.

ISIS has claimed credit for the mass shooting carried out by 29-year-old Mateen, the New York-born American citizen whose parents are from Afghanistan.

"This was an act of terror. Law enforcement and intelligence agencies are hard at work and we will learn more in the hours and days ahead. For now, we can say for certain that we need to redouble our efforts to defend our country from threats at home and abroad," Hillary said.

"That means defeating international terror groups, working with allies and partners to go after them wherever they are, countering their attempts to recruit people here and everywhere, and hardening our defences at home," she said.