"It is clear that the conditions upon which Syria's designation was based continue to exist, therefore an extension is warranted under the statute," DHS Secretary Kirstjen Nielsen said in a statement. "We will continue to determine each country's TPS status on a country-by-country basis."
Congress created TPS in 1990 as a humanitarian program to shield foreigners from deportation if their counties have been destabilized by conflict, natural disasters or other calamities.
But the Trump administration has moved to dramatically curtail the number of people allowed to stay in the country through the program, ending TPS for nearly 50,000 Haitians and 200,000 Salvadorans.
The administration has argued that its goal is to restore the original "temporary" intent of the program, and that TPS designation should be renewed only if the perilous conditions that produced it in the first place are unchanged. By canceling the protections for Salvadorans, Haitians and others who now face expulsion, the administration has picked up a bargaining chip in negotiations with Democrats who want TPS recipients included in an immigration deal.
Homeland Security officials said they will extend protections for Syrians who already possess the permits through Sept. 30, 2019, but would not accept more recent arrivals. DHS did not say how many Syrians have reached the United States since August 2016 but the number is not thought to be very large.
Syria's raging conflict has produced more than 5 million refugees. While a tiny portion of those have been accepted into the United States in recent years, the Trump administration has blocked their arrival almost entirely.
The number of Syrian refugees allowed into the country plunged in the past year, particularly with a freeze in place on applicants from 11 "high-risk" nations — Syria among them.
The United States admitted 12,587 Syrian refugees during the government's 2016 fiscal year, but that number began falling rapidly after President Trump took office, and he warned the program could be exploited by dangerous extremists.
State Department statistics show the United States has taken in just two refugees from Syria since Jan. 1, down from 1,318 in January 2017.
DHS officials said this week they will resume processing applications from high-risk countries during the second quarter of 2018, once they have implemented tougher screening procedures. Critics say the measures will make it even more difficult for desperate families fleeing the world's worst refugee crisis since World War II.
"America's claim of providing haven from persecution is not just under question but under threat," said David Miliband, president of the International Rescue Committee, a New York-based refugee aid organization.
"What the Trump administration has done through its successive bans and other administrative measures is slam the door on some of the most vulnerable people in the world," said Miliband, formerly Britain's top diplomat.
"These are victims of terrorism from ISIS and bombing raids by the Syrian government and the Russians," he said, using another name for the Islamic State.
Miliband said the fighting in Syria "is still burning" and continues to produce more victims, especially from areas under siege or bombardment by government forces. The largest numbers of refugees have gone to Turkey, Lebanon, Jordan and Germany.
The United States has hundreds of troops in Syria and continues to conduct airstrikes there. Islamic State forces that once controlled large swaths of the country have been decimated, but several other groups are fighting each other and the Russia-backed regime of Syrian President Bashar al-Assad.