The White House has signaled that President Obama’s pledge to reform the nation’s immigration system could happen later than the end of the summer, a deadline it set earlier this year.

Obama has pledged to circumvent Congress and unilaterally overhaul immigration, and has said previously that he would do so by the end of the summer. But he and other White House officials began suggesting in recent days that any action may happen later than planned.

During a news conference Thursday, Obama suggested that a flood of Central American children at the southwestern border, which peaked in the spring and is now abating, has had an impact on the potential timing of his decision.

“Some of these things do affect timelines, and we’re just going to be working through as systematically as possible in order to get this done,” he said.

A White House official said the timing of any potential action on immigration could influence migrations to the border.

When asked about a timeline Friday, White House press secretary Josh Earnest did not mention the end-of-summer deadline, which officials have been touting for weeks. But he also declined to say whether Obama would delay decisions on immigration until later this fall or after the November midterms.

“That’s putting the cart before the horse,” Earnest said.

Earnest said Obama has not yet received final recommendations from Attorney General Eric H. Holder Jr. and Homeland Security Secretary Jeh Johnson on how to address the immigration issue. The White House had previously said that those recommendations were to be given to Obama by the end of summer.

“So those who are speculating about how those recommendations might be implemented are a little ahead of themselves,” Earnest said.

Obama said Thursday that the flow of unaccompanied minors and other issues have “kept us busy, but it has not stopped the process of looking more broadly about how do we get a smarter immigration system in place while we’re waiting for Congress to act.”

Obama said he still believes “that if I can’t see congressional action, that I need to do at least what I can in order to make the system work better.”

Administration officials said earlier this month that the surge of children and Congress’s failure to pass broad immigration reform spurred Obama toward taking action by the end of the summer.

However, some Democrats in tight midterm election races, including Sens. Kay Hagan (N.C.), Mark Begich (Alaska) and Mark Pryor (Ark.), have said that Obama should not sidestep Congress when it comes to immigration reform.

Advocates expressed concern Friday about a potential delay, fearing that waiting until after the midterms could cause Obama even more political problems if Republicans win control of the Senate. Such a repudiation could make it more difficult for the president to move forward with bold executive action, forcing him to scale back on the kind of sweeping reforms that immigrant rights groups have been calling for, these advocates said.

David Nakamura contributed to this report.