Hillary Clinton coughs
Hillary Clinton coughsReuters

Democratic presidential frontrunner Hillary Clinton had an intense coughing fit during a speech on Monday, ironically forcing her to issue her promise to block Iran from obtaining nuclear weapons in a hoarse, barely audible whisper.

Speaking at the Jewish Federation of Greater Des Moines ahead of a key Iowa vote next week, Clinton began her warnings to Iran by saying "there must be consequences" - but then she was left speechless by a barking cough, even as conservatives warn her bark will not be as bad as her bite in keeping Iran in line.

Clinton kept coughing and sputtering for roughly a minute, unwrapping a throat lozenge and joking asking someone else to take over as she struggled to regain her lost voice, before she hoarsely continued.

"There must be consequences to snap sanctions back into place, and we have to make sure that Iran knows that if they try to develop or acquire nuclear weapons the United States will stop them," she finished in a hoarse whisper into the microphone.

Several minutes later her voice had returned, but the effect of her warning to Tehran over its nuclear ambitions was completely lost.

The controversial nuclear deal which Clinton supports allows Iran to inspect its own covert nuclear sites such as Parchin, and likewise Tehran can simply wait for the limitations on its nuclear program to expire under the deal in 15 years. The leading state sponsor of terror continues to show the US hostility, recently capturing ten sailors, and the US administration has admitted the windfall from lifted sanctions will go to terror.

Clinton had a similar ironic coughing fit during her lengthy testimony to the Benghazi Select Committee last October, over her questionable handling of the murder of four American officials. She succumbed to a long bout of coughing, requiring a cough drop and a lot of water to continue.

Tensions are high as Clinton faces a tight race with openly socialist Senator Bernie Sanders (I-VT), with polls showing her roughly tied with the 74-year-old in Iowa a week ahead of the caucus vote. Sanders also has a good chance of winning New Hampshire according to the polls.

Clinton's campaign has been run in the shadow of an ongoing investigation into her illegal use of an insecure private email server during her stint at secretary of state under US President Barack Obama, who she lost to in the 2008 Democratic primaries.

Last week it was revealed that some of her emails contained content beyond "top secret," requiring senior lawmakers to sign additional non-disclosure agreements to be able to view them, even though they had already signed off on the highest levels of clearance.

Clinton's released emails also appear to show she would be hostile to Israel in office; in 2011 she mulled a plan by a senior aide to stir up Palestinian unrest. Last November she said she would impose peace talks on the Jewish state - a statement also made by Republican front runner Donald Trump shortly afterwards in December.