They sent their resignation letter to Congress chief Sonia Gandhi and demanded to fix a deadline for carving out separate state.
Meanwhile, the Centre sought to mollify the Telangana supporters saying it has not diluted its stand on the statehood issue.
Law Minister M Veerappa Moily, in-charge of Congress affairs in AP, said, "The union government has not diluted its stand on Telangana."
The 13 ministers, who faxed their common resignation letter to Gandhi, met Chief Minister K Rosaiah en masse at the Secretariat here and informed him about their decision.
At the first meeting of the Telangana Joint Action Committee (JAC), formed on Friday, Dec 25, TRS chief K Chandrasekhar Rao is understood to have mooted a proposal to fix a deadline for the bifurcation of Andhra Pradesh.