Joe Biden told reporters in Kansas Sunday, to "focus on violations of the constitution this president has engaged in."
If an investigation shows that President Donald Trump pressured Ukraine to investigate former Vice President Joe Biden, the U.S. Congress may have no choice but to pursue impeachment, House Intelligence Committee Chairman Adam Schiff said on Sunday.
Trump and his allies, including Secretary of State Mike Pompeo, on Sunday defended the president's phone call -- reportedly the subject of a complaint made by an as-yet-unnamed whistleblower -- and escalated their attacks on Biden.
Schiff had previously shied away from calling for impeachment, but his comments on CNN's "State of the Union" showed his stance had shifted.
Trump, who has denied doing anything improper, told reporters on Sunday he had a great call with Zelensky and that he would have no problem with his personal attorney Rudy Giuliani testifying before Congress.
"I'm not looking to hurt Biden, but he did a very dishonest thing," Trump said Sunday morning as he left Washington for a rally in Houston.
Pompeo on Sunday said that Biden should be investigated if evidence shows he improperly intervened to protect his son.
"I do think if Vice President Biden behaved inappropriately, if he was protecting his son and intervened with the Ukrainian leadership in a way that was corrupt. I do think we need to get to the bottom of that," he said on ABC's "This Week."