WASHINGTON — President Barack Obama’s plan to shield more than 4 million immigrants living in the country illegally from deportation is on hold after a judge temporarily blocked the effort.

One program to help immigrants brought to the country as children was scheduled to kick in Wednesday, but instead Homeland Security Secretary Jeh Johnson said U.S. Citizenship and Immigration Services wouldn’t accept applications. And preparations for a second program aimed at protecting millions of parents of U.S. citizens and legal permanent residents have been idled until further notice.

U.S. District Judge Andrew Hanen wrote in a lengthy ruling that without a temporary injunction “the genie would be impossible to put back in the bottle.”

Twenty-six states sued the Obama administration last year to block the programs. A trial date has not been set.

Obama on Tuesday said he disagreed with the ruling.