Bolton says he is willing to testify in Trump impeachment trial

WASHINGTON - U.S. President Donald Trump's former national security adviser, John Bolton, said on Monday he is willing to testify in the expected Senate impeachment trial of the president, a surprise development that could potentially strengthen the case that Trump should be removed from office. As a top White House aide who witnessed many of the events that prompted the House of Representatives to impeach Trump in December, Bolton could provide new evidence about Trump's efforts to pressure Ukraine to investigate a political rival. Other witnesses during the House impeachment investigation testified that Bolton strongly objected to an effort by Trump's personal lawyer, Rudy Giuliani,...