Amazon and the United States Postal Service will offer Sunday delivery at no extra charge just in time for the holiday season in some parts of the United States.

The e-commerce company based in Seattle announced it has worked out a deal with the USPS to begin delivering packages in Los Angeles and New York metropolitan areas on Sundays.

For members of Amazon Prime, the $79-a-year subscription service that comes with free two-day shipping, you can place an order on Friday and have it on Sunday. "We're excited that now every day is an Amazon delivery day, and we know our Prime members, who voraciously shop on Amazon, will love the additional convenience they will experience as a part of this new service," said Dave Clark, Amazon's vice president of worldwide operations and customer service, in a statement on Monday. All Amazon members will have access to Sunday delivery, but Prime members are the only ones who get free two-day delivery.

The company said it plans to expand Sunday delivery to Dallas, Houston, New Orleans and Phoenix in 2014.

The announcement comes at tough period for the United States Postal Service, which has experienced a string of losses. In August, the Postal Service announced it had ended the third quarter of 2013 with a net loss of $740 million, which raised its year-to-date net loss to $3.9 billion.

Meanwhile, Amazon in October announced plans to increase seasonal hires to 70,000 for the upcoming holiday season.