President Barack Obama has accelerated his search for his next Supreme Court nominee, meeting in the Oval Office with one of the candidates, federal judge Sidney Thomas of Montana, a person familiar with the conversation says.

Obama's meeting with Thomas on Thursday was his first known formal interview for the upcoming vacancy on the court. He is holding conversations with other candidates, and it is not clear whether he has already had other personal meetings with contenders.

Vice President Joe Biden interviewed Thomas at the White House in a separate meeting Thursday, said the person familiar with the conversations, who spoke on condition of anonymity to discuss Obama's private deliberations.

The White House had no comment. A call to Thomas' chambers was not answered.

The personal time Obama devoted to Thomas suggests that the federal judge, well respected within legal circles but hardly a familiar name in Washington, is under a higher level of consideration by the president.

The news of his interview by the president and vice president works to the White House's advantage in signaling that Obama is giving a hard review to a candidate who comes from outside the Washington Beltway and does not neatly fit into conventional wisdom.