Michael Cohen, U.S. President Donald Trump's former long-term personal attorney, speaks to the press outside his Manhattan apartment before reporting to prison in New York, the United States, May 6, 2019. Michael Cohen began his three-year prison sentence on Monday after pleading guilty in December 2018 to a series of crimes, including campaign finance violations, tax evasion and lying to Congress. (Xinhua/Li Muzi)

Michael Cohen, U.S. President Donald Trump's former long-term personal attorney, speaks to the press outside his Manhattan apartment before reporting to prison in New York, the United States, May 6, 2019. Michael Cohen began his three-year prison sentence on Monday after pleading guilty in December 2018 to a series of crimes, including campaign finance violations, tax evasion and lying to Congress. (Xinhua/Li Muzi)

Michael Cohen, U.S. President Donald Trump's former long-term personal attorney, leaves his Manhattan apartment to report to prison in New York, the United States, May 6, 2019. Michael Cohen began his three-year prison sentence on Monday after pleading guilty in December 2018 to a series of crimes, including campaign finance violations, tax evasion and lying to Congress. (Xinhua/Li Muzi)

Michael Cohen, U.S. President Donald Trump's former long-term personal attorney, leaves his Manhattan apartment to report to prison in New York, the United States, May 6, 2019. Michael Cohen began his three-year prison sentence on Monday after pleading guilty in December 2018 to a series of crimes, including campaign finance violations, tax evasion and lying to Congress. (Xinhua/Li Muzi)

Michael Cohen (C, front), U.S. President Donald Trump's former long-term personal attorney, leaves his Manhattan apartment to report to prison in New York, the United States, May 6, 2019. Michael Cohen began his three-year prison sentence on Monday after pleading guilty in December 2018 to a series of crimes, including campaign finance violations, tax evasion and lying to Congress. (Xinhua/Li Muzi)

Michael Cohen, U.S. President Donald Trump's former long-term personal attorney, leaves his Manhattan apartment to report to prison in New York, the United States, May 6, 2019. Michael Cohen began his three-year prison sentence on Monday after pleading guilty in December 2018 to a series of crimes, including campaign finance violations, tax evasion and lying to Congress. (Xinhua/Li Muzi)

Michael Cohen, U.S. President Donald Trump's former long-term personal attorney, leaves his Manhattan apartment to report to prison in New York, the United States, May 6, 2019. Michael Cohen began his three-year prison sentence on Monday after pleading guilty in December 2018 to a series of crimes, including campaign finance violations, tax evasion and lying to Congress. (Xinhua/Li Muzi)

Michael Cohen (R, front), U.S. President Donald Trump's former long-term personal attorney, leaves his Manhattan apartment to report to prison in New York, the United States, May 6, 2019. Michael Cohen began his three-year prison sentence on Monday after pleading guilty in December 2018 to a series of crimes, including campaign finance violations, tax evasion and lying to Congress. (Xinhua/Li Muzi)