Former U.S. National Security advisor John Bolton is not going to voluntarily appear in Congress to testify as part of an investigation to impeach President Donald Trump, The Wall Street Journal reported referring Bolton’s lawyer Charles Cooper. 

Earlier, CNN reported that Bolton was invited to Congress to testify as part of an investigation into impeachment of President Donald Trump. However, the channel did not specify whether Bolton was invited or summoned.

Cooper reportedly notified the House Committee of Congress that his client does not plan to voluntarily agree to the call. 

According to the lawyer, he was ready to receive a summons on behalf of Bolton at any time.

A source familiar with the situation told the publication that House committees want Trump's former national security advisor to appear in Congress on November 7.

Democrats began impeaching Trump for allegedly putting pressure on Ukrainian President Volodymyr Zelenskyy to investigate Trump's political opponent, former vice president Joe Biden. Trump says that he urged the Ukrainian authorities to only fight corruption.