Special counsel Robert Mueller is investigating a number of official actions taken by President Donald Trump during his presidency, according to new reports Wednesday from The New York Times and The Washington Post.

In recent weeks, Mueller has asked the White House to produce all documents, emails and correspondence related to at least 13 different subject areas, according to the reporting, which was later confirmed by other outlets.

The areas include Trump's decision, early in his presidency, to fire his national security adviser, Michael Flynn, over how Flynn handled revelations about foreign lobbying that came to light after Trump was sworn in.

Mueller is also interested in Trump's decision in May to fire FBI Director James Comey; in any meetings Trump and Comey had during Comey's tenure; and in how the White House announced Comey's firing.

One subject seemed to catch Washington by surprise Wednesday: A request for documents related to Trump's Oval Office meeting in May with then-Russian Ambassador Sergey Kislyak.

It was at that meeting, shortly after Trump had fired Comey, that the president is reported to have told Kislyak, "I just fired the head of the FBI. He was crazy, a real nut job." Trump then appeared to explain to Kislyak that Comey's firing would relieve "pressure" on Trump. "I faced great pressure because of Russia. That's taken off," Trump reportedly said, according to a source who spoke to The New York Times.

Read the Times' reporting, which broke the story, here. The Post quickly followed with a more detailed breakdown of the 13 categories of Mueller's inquiry. Read that here.