By Patricia Zengerle

WASHINGTON (Reuters) - The Obama administration believes it will be able to process many more Syrian refugees in the last half of fiscal 2016 than in the first six months, allowing it to meet its goal of admitting at least 10,000 by Sept. 30.

In a letter to Democratic Senator Richard Durbin seen by Reuters on Thursday, the White House said it has allocated additional staff and added more processing locations in the Middle East to expedite the screening process without compromising U.S. security.

"Therefore, we expect to admit more Syrians in the third and fourth quarters of fiscal year 2016 than we did in the first and second quarters to meet our goal of admitting at least 10,000 Syrian refugees this fiscal year," the letter said.

The administration's move is in sharp contrast to recent anti-refugee rhetoric by many Republicans, especially since the killings in Orlando on Sunday raised fears of attacks.

Donald Trump, the presumptive 2016 Republican presidential nominee, has called for the refugee resettlement program to be suspended, saying "We don't know who they are. They have no documentation, and we don't know what they're planning."

Backers of the administration's plan dispute such statements, citing the extensive screening process the Syrian refugees undergo.

So far, the United States has offered refuge to far fewer of the millions fleeing the war in Syria than many of its closest allies. Germany has taken in hundreds of thousands and Canada admitted nearly 30,000 between November 2015 and May 1, 2016.

The letter said the administration had set up a temporary processing center in Jordan and expanded operations in Turkey. It also has restarted interviews in neighboring Lebanon, and begun limited processing in Erbil, Iraq.

Durbin was a lead author of a letter to President Barack Obama in May, which was signed by more than half the Democrats in the Senate and urged the president to move more quickly to admit Syrians.

By mid-May, only 1,736 Syrians had been allowed into the country, a pace that would have fallen far short of the 10,000 goal for the full year.

The letter seen on Thursday was the administration's response to the one sent in May.

Obama's plan to admit 10,000 Syrians was met with a firestorm of criticism in the United States, mostly from Republicans who say that violent militants could enter the country by posing as refugees. More than 30 governors, most of them Republicans, have tried to keep refugees out of their states.

(Reporting by Patricia Zengerle; Editing by John Walcott and Sandra Maler)