Robert Mueller moves closer to possible interview of President Trump, sources say

WASHINGTON (KABC) -- Special counsel Robert Mueller has indicated to President Donald Trump's attorneys that investigators are moving closer to a possible interview of the chief executive, in which they would seek answers on two key matters, ABC News has learned.

Prosecutors are interested in the circumstances surrounding the firing of former national security advisor Michael Flynn, as well as the firing of ex-FBI Director James Comey, sources said.

The president's lawyers have been researching and composing arguments with regard to how possible negotiations with Mueller's office could be handled if a formal request to interview Trump is presented.

Trump's legal team declined to comment.

The group has been discussing potential options, including submitting written responses in for the form of a questionnaire or an in-person inquiry.

Asked if the president would be open to such an interview, White House press secretary Sarah Huckabee Sanders on Tuesday told reporters he would be "fully cooperative" with the special counsel.

ABC News and the Associated Press contributed to this report.