Republicans said the Obama administration should be focused on tackling what they called a border crisis. The expansion would instead essentially open an entirely new channel for Central American families escaping endemic violence to gain legal entrance to the United States.

“What we have seen is that our current efforts to date have been insufficient to address the number of people who may have legitimate refugee claims, and there are insufficient pathways for those people to present their claims,” Amy Pope, a deputy Homeland Security adviser, said in a conference call to announce the changes. She said the revisions showed a recognition that “the criteria is too narrow to meet the categories of people who we believe would qualify under our refugee laws, but they just don’t have the mechanism to apply.”

The White House also said it had reached an agreement with Costa Rica to serve as a temporary host site for the most vulnerable migrants from El Salvador, Guatemala and Honduras while they wait to be processed as refugees. These migrants would first undergo security screening in their home countries. Costa Rica would accept up to 200 people at a time among those who are found to be eligible, for periods of six months.

The United Nations high commissioner for refugees has agreed to set up an unusual process to review requests from potential refugees while they are in their home countries. Administration officials also said they would begin reviewing applications from refugees in their home countries, a step they hoped would discourage people from making the dangerous trip to the United States border.

Republicans said the expansion was the latest example of the White House’s misuse of its authority.

“Once again, the Obama administration has decided to blow wide open any small discretion it has in order to reward individuals who have no lawful presence in the United States with the ability to bring their family members here,” Representative Robert W. Goodlatte, Republican of Virginia and the chairman of the House Judiciary Committee, said in a statement. “Rather than take the steps necessary to end the ongoing crisis at the border, the Obama administration perpetuates it by abusing a legal tool meant to be used sparingly to bring people to the United States and instead applying it to the masses in Central America.”