This was announced by White House Press Secretary Karine Jean-Pierre.
However, she omitted the details of the president's reaction.
Greiner was detained on February 18 at Sheremetyevo Airport on suspicion of trying to illegally import banned substances into Russia.
Her luggage was checked using X-ray equipment and found vapes (cartridges for an electronic heating system) with cannabis oil.
Earlier, an American journalist suggested arresting Russian Washington Capitals hockey player Alexander Ovechkin in the United States in response to Greiner's detention.