Asserting a public demand for a greater measure of protection, Republicans are ready to push legislation through the House erecting fresh hurdles for Syrian and Iraqi refugees trying to enter the United States. President Barack Obama promised a veto.

While many Democrats mocked the House effort as election-season grandstanding, political pressures were pushing others to support the measure or seek to change other entry procedures.

"We are a compassionate nation. We always have been, and we always will be," said House Speaker Paul Ryan, R-Wis. "But we also must remember that our first priority is to protect the American people."

Republicans were bringing the bill to the House floor on Thursday, less than a week after a burst of bombings and shootings killed 129 people in Paris, wounded many more and revived post-9/11 jitters in the U.S. and other countries. The Islamic State group has claimed responsibility for the massacres.

The measure would require the FBI to conduct background checks on Syrian and Iraqi refugees. It would oblige the heads of the FBI and Homeland Security Department and the director of national intelligence to certify to Congress that each refugee "is not a threat to the security of the United States."

Republicans said the bill contained no religious tests for the refugees - a split from former Florida Gov. Jeb Bush and Sen. Ted Cruz of Texas, GOP presidential contenders who have suggested giving preferences to Christians. Democrats said the measure in effect targeted Muslims, who comprise the majority of Iraqis and Syrians.

In a statement assuring a veto, the White House said the GOP bill would not improve Americans' security. It said the legislation "would unacceptably hamper our efforts to assist some of the most vulnerable people in the world, many of whom are victims of terrorism, and would undermine our partners in the Middle East and Europe in addressing the Syrian refugee crisis."

Currently, the refugee screening process typically takes 18 to 24 months and includes interviews, fingerprinting and database crosschecks by several federal agencies. Syrians undergo additional screening involving data from the U.N. Refugee Agency and interviews by Homeland Security Department officials trained to question Syrians.

Republicans said that with Islamic State militants openly threatening to attack the U.S. in a recent video, that system isn't sufficient to ensure Americans that refugees entering the United States aren't extremists bent on attacking the country.

"The status quo is not acceptable," said House Homeland Security Committee Chairman Michael McCaul, R-Texas, who wrote the bill with Rep. Richard Hudson, R-N.C. "The American people want us to act in light of what's happened."

Several conservative Republicans said they'd support the House GOP bill but called it symbolic since Republicans lack the votes needed to override an Obama veto. Many of them are considering pushing the issue in a massive spending bill due by Dec. 11 - a measure that if vetoed would lead to a government shutdown.

"We don't have enough Democrats willing to protect American lives to override the veto," said Rep. Mo Brooks, R-Ala.

The Obama administration wants to increase the 70,000 refugees to be admitted from around the world this year by 10,000, with much of the increase for Syrians.

The White House said that of 2,174 Syrians admitted to the U.S. since the Sept. 11, 2001 attacks, none has been arrested or deported because of allegations they harbored extremist ambitions.

Democrats said the GOP legislation would in effect completely block Syrian and Iraqi refugees from entering the country because officials cannot absolutely guarantee that they wouldn't be threats, and because it would take two years to install new procedures the bill would mandate.

Rep. Bill Pascrell, D-N.J., said that with next year's presidential election approaching, Republicans were using the bill to show conservative voters that they want to "keep away the foreign invaders."

Even so, there were signs many Democrats felt uncomfortable flatly opposing the GOP effort.

The 15-member Blue Dog Coalition of moderate Democrats said it would support the legislation. Rep Kurt Schrader, D-Ore., said the measure makes the system "stronger and makes it safer for America to do the right thing by accepting legitimate refugees."

Mississippi Rep. Bennie Thompson, top Democrat on the Homeland Security panel, and other Democrats were proposing an alternative blocking admission for any refugees the government finds have not fully established their identity.

Sen. Dianne Feinstein, D-Calif., and Sen. Jeff Flake, R-Ariz., said they would introduce a bill restricting visas for any individuals who had been in Iraq or Syria in the past five years.