US judge temporarily halts Obama's immigration orders
Twenty-six states have filed a lawsuit to contest the policy that would prevent the deportation of as many as five million people.
The decision by US District Judge Andrew Hanen did not rule on the merits of the case, but it does allow the states more time to contest the order.
Some parts of the policy would have started to take effect on Wednesday.
The US Department of Justice said it plans to appeal against the ruling and on Tuesday the White House defended the legality of its policy.
President Obama took the action in November after immigration-reform efforts had failed repeatedly in Congress.
Without a preliminary injunction, Judge Hanen wrote that the states will "suffer irreparable harm in this case".
The coalition of states, led by Texas and made up of mostly conservative states in the South and Midwest, say the order would increase costs for law enforcement, health care and education.
President Obama's unilateral move angered Republicans who are working to stop the executive action.
The House has approved a bill that would remove funding for the policies from the Department of Homeland Security's budget. The measure has failed to pass the Senate and President Obama is expected to veto the bill.
Republicans hailed Mr Hanen's injunction.
"The Texas court decision reached last night is a major turning point in the fight to stop Obama's lawless amnesty," said Senator Ted Cruz, a Texas Republican.
The White House has said Obama's executive order is not out of legal bounds and that the US Supreme Court and Congress have said federal officials can set priorities in enforcing immigration laws.Analysis: Thomas Sparrow, BBC Mundo, Washington
Far from the political debate that has dominated immigration, Monday's ruling has the potential to affect millions of undocumented immigrants across the country.
In fact, about 270,000 undocumented immigrants will be immediately affected. They came to the US as children and are eligible to apply under a programme that was due to begin this week but has now been postponed.
More generally, the halt may also increase the fear many Hispanics around the country feel about releasing their personal information for a programme that is limited in scope, temporary in nature and could be reversed by decisions like the one on Monday.
During a recent trip to the US-Mexico border in Texas, we spoke to many undocumented Hispanic immigrants who clearly expressed those fears.
One of them even said that "with this announcement, there is no hope, you don't know where your future lies," referring to president Obama's November executive action.
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Twelve states as well as Washington DC and the US Conference of Mayors have come out in support of President Obama's action, saying it would stimulate the economy.
The first of President Obama's orders - to expand a programme that protects young immigrants from deportation if they were brought to the US illegally as children - was set to start on Wednesday.
The other major part of President Obama's order, which extends deportation protections to parents of US citizens and permanent residents who have been in the country for some years, was not expected to begin until 19 May.