Can't access site to make payment...what gives???

Getting this message when trying to log on: "We're sorry. Citi.com is temporarily unavailable. Citi.com and Citibank Online are currently unavailable. If you need immediate assistance, please call 1-800-374-9700 (TDD/TYY: 1-800-788-0002). We apologize for any inconvenience and appreciate your patience."