The House Foreign Affairs, Intelligence and Oversight committees said Giuliani had said on national television that he asked the government of Ukraine to "target" former Vice President Joe Biden.

The three committee chairmen said letters were also sent seeking documents and setting deposition dates for businessman Lev Parnas and real estate investor Igor Fruman, who, according to various media accounts, helped introduce Giuliani into top Ukrainian political circles.

A letter was also sent to Semyon "Sam" Kislin, a Ukrainian immigrant who has had business ties to Trump and served on Giuliani's city economic development corporation when Giuliani was mayor of New York.

Parnas' deposition was set for Oct. 10, Fruman's for Oct. 11 and Kislin's for Oct. 14.