Hillary Clinton phones Bill as he makes campaign rally speech

With the Iowa caucuses just three weeks away, Bill Clinton is busy rallying support for his presidentially-hopeful wife.

The former president was in the middle of a speech on Thursday when his phone rang.

Who was calling him? His wife.

On Thursday, he made his first campaign stop in the state where he was speaking at a rally in support of Hillary when his phone began to buzz.

"There are other issues that keep Americans up at night and... my phone's ringing," he said.

An embarrassed Bill went on: "I'll have to call Hillary back and explain why I couldn't take it."

The former president was surprised and the crowd laughed at the unexpected moment.

Following the unplanned call from Hillary, he continued to speak to the crowd of more than 500.

He went to criticize Republicans who plan to repeal Obamacare and President Obama's gun control reforms.

Clinton also praised Hillary as "the best change-maker I ever saw."

See Bill and Hillary Clinton as they fell in love: