President Obama threatened late Wednesday to veto legislation aimed at improving screening for Syrian refugees, potentially putting the White House and Congress on a collision course in a matter of days.

The veto threat came as the House was preparing the bill -- which sets high hurdles for refugee admission including FBI background checks and sign-offs by top officials -- for floor action as early as Thursday. In a committee meeting, Rep. Pete Sessions, R-Texas, accused the president of confusing the public about the intentions of the legislation.

Moments later, the White House issued a statement defending the current screening process and claiming the changes called for under the bill would create "significant delays and obstacles" for the existing vetting program.

"Given the lives at stake and the critical importance to our partners in the Middle East and Europe of American leadership in addressing the Syrian refugee crisis ... [Obama] would veto the bill," the White House said.

Honduran authorities have detained five Syrian nationals who were trying to reach the United States using stolen Greek passports, but there are no signs of any links to last week's attacks in Paris, police said.

The Syrian men were held late on Tuesday in the Honduran capital, Tegucigalpa, on arrival from Costa Rica, and had been planning to head to the border with neighboring Guatemala. The passports had been doctored to replace the photographs with those of the Syrians, police said.

"We received information from (fellow) police services that these five Syrians left Greece and passed through Turkey, Brazil, Argentina and San Jose in Costa Rica before finally reaching Tegucigalpa," said Anibal Baca, spokesman for Honduras' police. "They are normal Syrians."