AUSTIN, Texas (AP) — Texas’ plan to arrest migrants who enter the U.S. illegally is headed to the Supreme Court in a legal showdown over the federal government’s authority over immigration.

The high court on Monday blocked Texas’ immigration law from going into effect until March 13 and asked the state to respond by March 11. The law was set to take effect Saturday, and the court’s decision came just hours after the Justice Department asked it to intervene.

Republican Gov. Greg Abbott signed the law in December and for months has unveiled a series of escalating measures on the border that have tested the boundaries of how far a state can go keep migrants from entering the country.

The law would allow state officers to arrest people suspected of entering the country illegally. People who are arrested could then agree to a Texas judge’s order to leave the country or face a misdemeanor charge for entering the U.S. illegally. Migrants who don’t leave after being ordered to do so could be arrested again and charged with a more serious felony.

The Justice Department told the Supreme Court that the law would profoundly alter “the status quo that has existed between the United States and the States in the context of immigration for almost 150 years.” It went on to argue that the law would have “significant and immediate adverse effects” on the country’s relationship with Mexico and “create chaos” in enforcing federal immigration laws in Texas.