Chicago Mayor Rahm Emanuel says he will seek a court order to end a teachers strike set to enter its second week.

Emanuel said the strike is illegal under state law.

The Chicago teachers union decided Sunday to continue its weeklong strike, extending an acrimonious standoff with Emanuel and the city schools.

Emanuel says, "This was a strike of choice and is now a delay of choice that is wrong for our children."

The union says it needs more time to meet its members to discuss a tentative contract reached over the weekend.