President Obama is standing by his decision to ramp up the admission of Syrian refugees to the United States even after three refugees from Islamic countries attacked people in Germany over the last week.

The 10,000 Syrian refugees the president wants to admit by October are subjected to more thorough screening and vetting than anyone trying to enter the United States, White House spokesman Josh Earnest stressed Monday.

"That's why the president has confidence ramping up the number of refugees admitted to the United States," Earnest told reporters during his daily briefing. "Obviously, almost all of them are innocent people fleeing violence in their own countries — some of them are innocents fleeing genocide.

"The president feels like the U.S. has a responsibility to do our part to try to provide relief for people fleeing that type of violence," he said.

Stressing that Obama's top priority is the safety and the security of the American people, Earnest said the screening process for Syrian refugees involves running their names through a wide variety of U.S. and international law enforcement, military and intelligence agency databases.

"So I can understand why people are concerned about our national security — the president is concerned about our national security ... That is why he has ensured that refugees admitted to the United States are subjected to all the screening," he said.

The total number of Syrian refugees admitted to the United States this fiscal year has risen to roughly 6,700, according to several reports that cite the State Department.

After a slow start, the State Department hired more employees to provide screenings, and began admitting refugees at a more rapid clip this summer.

German authorities have said two Syrian refugees and one Afghan refugee are responsible for three attacks over the last week.

On Sunday, a 27-year-old Syrian refugee died when a bomb he was carrying went off outside a music festival in Ansbach, in the southern German state of Bavaria. Twelve people were injured, one seriously.

Just a few hours earlier, another Syrian refugee attacked and killed a Polish woman with a knife and injured two others at a fast-food restaurant in the town of Ruetlingen in southwest Germany.

Days earlier, a 17-year-old Afghan refugee wielding an ax attacked people on a train in southern Germany before police killed him.

The biggest attack in Germany over the last week, however, was not committed by a refugee. German authorities say an 18-year-old dual German-Iranian national shot and killed nine people in a shopping mall in Munich July 22. Police said the young man was mentally unstable.