By Sebastien Malo

NEW YORK (Thomson Reuters Foundation) - Refugee advocates have welcomed an assessment by a senior U.S. official that the United States is on track to hit a target of resettling 10,000 Syrian refugees by the end of September.

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.

President Barack Obama had called for a sharp increase in the number of Syrian refugees resettled in the United States in the 2016 fiscal year. But the plan to admit 10,000 Syrians was met with a firestorm of criticism, mostly from Republicans who say militants could enter the country by posing as refugees.

On Thursday, Homeland Security Secretary Jeh Johnson told Congress the United States had already approved 5,000 Syrian refugees for resettlement and was likely to meet the target.

Naomi Steinberg, director of Refugee Council USA, said reaching the halfway mark was an important milestone.

"We're hoping that this is just laying the foundation for bringing in more Syrian refugees in upcoming fiscal years," she told the Thomson Reuters Foundation.

Nearly 5 million Syrians have fled their country since the outbreak of civil war in 2011, according to the U.N. refugee agency UNHCR.

The slow pace of the U.S. admission process, which entails vetting refugees by means of interviews, medical exams and security checks, contrasts with the speed of refugee processing in neighboring Canada.

Jen Smyers, a spokeswoman for Church World Service, an international humanitarian organization and one of the agencies resettling refugees in the United States, said meeting the 10,000 target would give Washington the "moral leadership" to ask other nations to do more.

"We're certainly heartened to hear that the administration is taking very seriously their commitment and their responsibility," Smyers said.

"(But) the reality is that while the U.S. actually meeting its goal is certainly encouraging, we're still not resettling as many refugees as we should be."

On Wednesday, the U.S. ambassador to the United Nations, Samantha Power, took aim at nations she said are failing to help refugees fleeing war in the Middle East and elsewhere, calling anti-immigrant rhetoric and sentiment misguided.

Stacie Blake of the U.S. Committee for Refugees and Immigrants, said even the 10,000 goal fell far short of what was needed given the scale of the crisis.

Her organization last year called for the resettlement of 100,000 Syrian refugees in the United States.

"That's really the level of response that we think is required with a global emergency of 65 million people in need," she said.

(Reporting by Sebastien Malo, Editing by Ros Russell; Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, property rights and climate change. Visit http://news.trust.org)