Sen. Rand Paul claimed President Trump was upholding a mandate from Congress to ensure foreign aid was not being given to a corrupt country as he justified a White House decision to delay the money approved by lawmakers for Ukraine at the center of impeachment.

"It really gets to the heart of this; this is a disagreement about policy," the Kentucky Republican said Sunday on CNN's State of the Union. "This isn't about the Constitution or the president breaking the Constitution. Foreign aid is always contingent upon behavior. In fact, the money we gave them to give to Ukraine, it says specifically in the law he has to certify that they are less prone to corruption. I mean, he was instructed by Congress to do exactly what he asked to be done."

Democrats are impeaching Trump on the heels of an intelligence community whistleblower report who warned the president conditioned military aide to Ukraine on the country opening an investigation into alleged corrupt practices by one of Trump's chief political rivals, former Vice President Joe Biden.

White House chief of staff Mick Mulvaney confirmed the aid was briefly withheld earlier this year and said the U.S. government does so "all the time." However, he later walked back his admission.

Democrats have said Trump abused his power by conditioning "official acts" for "personal political benefit." Paul, an outspoken isolationist, pushed back on allegations from his Democratic colleagues and defended Trump, saying the president was legitimately concerned the aid might not be spent the way it was intended when it was approved by Congress.

"His opinion on foreign aid is similar to mine," Paul said of Trump. "Mine is a little more exacting."

