White House plans to allow thousands more refugees into the United States face stiff opposition on Monday in the U.S. Congress, where Republican lawmakers demanded the right to review, and reject, the effort, citing fears of terrorism.

Secretary of State John Kerry on Sunday announced an increase of 15,000 per year for the next two years in the number of refugees the country takes in. He did not say how many would be from Syria.

Under current law, Congress does not have to approve the Democratic administration's plan. But the House of Representatives and Senate, both controlled by Republicans, would have to appropriate money to pay for any expanded effort.