U.S. prosecutors asked a federal judge Wednesday to delay the corruption trial of New Jersey Senator Bob Menendez and his wife by at least two months, after lawyers for Nadine Menendez said she faced a serious medical condition that required surgery.

In a letter to U.S. District Judge Sidney Stein in Manhattan, prosecutors asked that the May 6 trial date be pushed back to July or August, though they still oppose granting the Menendezes' requests to be tried separately.

Prosecutors said the government "takes seriously the unexpected medical development," and that an adjournment would let the Democrat senator focus on his wife's health. They opposed Nadine Menendez's request for an indefinite adjournment.

Lawyers for the senator and his wife did not immediately respond to requests for comment.

Nadine Menendez has not disclosed her medical condition, but her lawyers said it would require surgery within four to six weeks and potentially significant follow-up treatment.