A top adviser to presidential hopeful Sen. Bernie Sanders (I-Vt.) on Tuesday lashed out at former Vice President and fellow Democratic hopeful Joe Biden for reportedly suggesting that he opposed the Iraq War from the very beginning.

As a senator, Biden voted in favor of the measure authorizing military action in Iraq in 2002.

"We've got a pathological liar in the White House, we don't need pathological lies about the Iraq War from the Democrats when we're confronting the most dangerous president in modern history," David Sirota, an adviser and speechwriter for Sanders's 2020 campaign said.

The Biden campaign didn't immediately respond to The Hill's request for comment.

In response to an Iowa voter who expressed concern about Biden's foreign policy record, the former vice president over the weekend said that he opposed the Iraq War "from the very moment" it began in 2003, according to CNN.

"The president then went ahead with 'Shock and Awe,' and right after that ― and from the very moment he did that, right after that ― I opposed what he was doing and spoke to him," Biden said of President Bush on Saturday.

Sirota's remarks come as the battle between Biden and Sanders has intensified ahead of the critical Iowa Cacususes next month.

During an interview with CNN's Anderson Cooper on Monday, Sanders tore into Biden over his record on foreign policy and trade among other issues.

Sirota said Sanders will continue to contrast their differences, arguing that voters need to be able to make informed decisions. The Sanders campaign has long claimed that, unlike Biden, the Vermont independent's record, particularly his vote against the Iraq War, is viewed as a strength rather than a weakness.

"I expect that this contrast will be a central focal point as we come down the stretch here in giving voters the ability to make an informed choice on the policy issues," he said.

- Tess Bonn