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The United States is developing an expanded training program for local Kurdish and Arab border guards in Syria, the top U.S. commander for the Middle East said, to help head off the "significant risk" of Islamic State fighters regrouping in the country. It's an effort that could entail a longer term American and allied commitment.

Army Gen. Joseph Votel, head of U.S. Central Command, said in a recent telephone interview with The Associated Press that the border control training would reflect major combat operations in Syria ending and the U.S.-led coalition shifting focus to stabilizing areas seized from IS. Washington also wants to root out the remaining insurgents in Syria.

Votel wouldn't say exactly how many U.S. forces will remain in Syria or for how long, but said the American military campaign in Syria will remain consistent. He suggested no imminent decrease in the U.S. troop level on the ground in Syria, which currently exceeds 2,000.

The border security forces "will help prevent resurgence of ISIS and will help bring control," Votel said, adding that training will take place inside Syria. "We do it right where it's needed."

The training will include instruction in interrogation, screening, biometric scanning and other skills to help U.S.-backed Syrian forces identify insurgents who may be trying to cross into Syria from neighboring countries. The U.S. is discussing possible contributions from its coalition partners in Europe and the Arab world. They may be more willing to contribute troops now that the emphasis is on stabilization and peacekeeping, not fighting.

The increased training could prove critical to restoring civil order in areas where IS was ousted, and to protecting Syria's troubled and porous frontiers with Iraq, Turkey, Lebanon and Jordan. Pockets of militants are entrenched throughout Syria's border areas, so any campaign to eliminate them will be difficult. The U.S.-led coalition only controls part of the Syrian border.

It also may raise questions about a shifting U.S. mission in Syria. President Donald Trump has made clear his priority is defeating foreign terrorist organizations, and not more amorphous efforts to build nations or settle internal disputes in foreign lands. Propping up a bigger border force could mean a longer U.S. campaign in Syria at a time the Trump administration has no practical relationship with the nation's government and still talks about a political transition that might end Syrian President Bashar Assad's rule.

Assad's government and its partners — including Russia and Iran — have been separately trying to re-impose security in parts of the country they control. They've fought IS, al-Qaida-linked militants and other more moderate rebel groups on the battlefield over the last year or so, but the sustainability of their successes is unclear.

Votel pointed to Russian President Vladimir Putin's declaration this month that IS was defeated in eastern Syria. Just days later, IS took over six villages in the area.

"You just can't go in and have a fight and drop a bunch of bombs and then step away from it and think that the problem is solved," said Votel. "This is a reminder of just how resilient and capable this organization is, and how we have to really make sure, as we complete these operations, that we've done it very thoroughly."

Such thinking appears to be coloring U.S. decisions about keeping troops in Syria.

The military doesn't want to "keep unnecessary capabilities, unnecessary presence on the ground where we don't need it," Votel said. But he said changes will only occur when conditions in Syria improve and local security forces can secure and retain control over their own towns and cities.

No one in the Trump administration has made a similar declaration of victory in Syria. Not only do national security and military leaders believe celebrations may be premature, but a claim of victory also would raise legal questions about the American military's continued presence in Syria, without the Assad government's consent.

By emphasizing the persistent threat posed by Islamic State fighters, the U.S.-led coalition can justify staying in Syria to give troops more time to improve local forces, including those opposing Assad. They could, in theory, end up serving as a deterrent to any Assad campaign to defeat all his internal opponents and advance the U.S.' preferred outcome: Peace talks between Syria's government and "moderate" rebels.

Votel said no one in the U.S. government has tried to force such a victory declaration.

"I don't feel any pressure on this," he said.