There has been no indication that Mr Mueller told the president to fire Mr Comey.
This story will be updated as new information becomes available.
The Justice Department's investigation into Russian involvement in the 2016 election is looking at Kushner's multiple roles in the Trump administration, including the Trump campaign's 2016 data analytics operation; his relationship with former national security adviser Michael Flynn; and Kushner's own contacts with Russians, according to U.S. officials briefed on the probe.
The president expressed annoyance about news reports that the probe is now believed to include an examination of whether he obstructed justice by firing FBI Director James Comey, who had earlier led the Russian Federation investigation. Last week, Comey testified in a Senate hearing that he believed he was sacked "because of the Russian Federation investigation".
The American people deserve to know just how deeply Moscow delved into our election process - and whether any Americans were connected to the interference with our democratic process. An official confirmed to Fox News that Trump was referring to Rosenstein in the statement. An aide familiar with the meeting said it was held to discuss the investigations, including ways that the parallel inquiries don't interfere with or overlap one another.
Trump's Twitter response followed days of intensifying criticism of Mueller from some conservatives who have charged the former Federal Bureau of Investigation director and his team with political bias and have claimed his relationship to Comey and an earlier meeting with Trump amount to conflicts of interest.
The department would not comment on the record on whether Trump, who has repeatedly complained about leaks on the case, requested the statement.
He wrote in multiple social media posts that he views Mueller - a long-serving former Federal Bureau of Investigation director respected by both parties - as leading a biased probe with the singular aim of dislodging Trump.
Grassley announced the investigation in a letter to California Sen.
"The message the president is sending through his tweets is that he believes the rule of law doesn't apply to him and that anyone who thinks otherwise will be fired", Feinstein said. Dianne Feinstein, the top Democrat on the Senate Judiciary Committee, in a statement.
"After 7 months of investigations & committee hearings about my 'collusion with the Russians, ' nobody has been able to show any proof". Grassley said Comey's dismissal and Comey's testimony on Lynch should be looked at together, noting that Comey "took the opportunity in his testimony to clear his own name by denouncing as false the administration's claims that the FBI rank-and-file had lost confidence in Mr. Comey's leadership in the wake of the Clinton email investigation".