Gov. Chris Christie joined the ranks of governors telling the federal government their states won't accept Syrian refugees Tuesday — though it's not clear he has the authority to turn them away entirely.

In a letter to President Barack Obama Tuesday, Christie said that is first priority is keeping New Jersey safe, and "the threat posed to New Jersey by ISIS is very real."

The move is something of an about-face for Christie, who two months ago, on MSNBC, said the United States needed to make a determination as to how many refugees would be admitted — and would have to “sit down with our allies and figure out how we can help, because America is a compassionate country.”

Monday, on the conservative Hugh Hewitt radio show, Christie said he'd shut out refugees from the U.S. — even orphans under 5 years old (an example Hewitt brought up).

According to State Department figures, 75 refugees have been settled in New Jersey since Jan. 1.

Christie's one of a growing chorus of governors saying they'll shut refugees out following Friday's deadly terrorist attacks in Paris. The fingerprints of one of the attackers were found to match those of a Syrian refugee who passed through Greece in October. But Lavinia Limon, president and CEO of the U.S. Committee for Refugees and Immigration, told the Associated Press that under the Refugee Act of 1980, governors cannot legally block refugees.

In his letter to Obama, Christie quoted FBI Director James Comey, speaking at a congressional hearing last month: "We can query our database until the cows come home, but there will be nothing show up because we have no record of them."

(The full quote was actually preceded by "If someone has never made a ripple in the pond in Syria in a way that would get their identity or their interest reflected in our database ..." — though that wasn't reflected in Christie's letter).

Christie said when the federal government places a refugee with the help of a nongovernmental organization, the host state isn't notified.

"As a result, New Jersey is left to depend upon the broken federal monitoring system described by the FBI director to ensure that a person places here is not a threat to our resdients," Christie wrote.

He referenced the case of a New Jersey man who pleaded guilty to conspiring to provide material support to ISIS — though that man was reportedly raised by a Catholic mother and a Jewish father in Fort Lee. Christie also noted New Jersey borders New York, a prime target for terrorists.

Christie said Obama should halt his plans to accept more Syrian refugees into the United States — Obama recently decided raise the nation’s annual limit of 70,000 refugees by 10,000, with most of the new slots for Syrians — and should instead "channel the compassionate urge to protect innocent lives to encouraging our allies in the region to accept these refugees with our support.

"I cannot allow New Jersey to participate in any program that will result in Syrian refugees — any one of whom could be connected to terrorism — being placed in our state," Christie wrote.

He said the state's Department of Human Services wouldn't participate in the resettlement of Syrian refugees, and he's requesting nongovernmental organizations notify the state's Office of Homeland Security about any they've helped settle.

"Neither you nor any federal official can guarantee that Syrian refugees will not be part of terroristic activity," Christie wrote. "As such, opening our door to them irresponsibly exposes our fellow Americans to unacceptable peril.'