Azim Isabekov, who was approved as prime minister by the Kyrgyz parliament following a standoff between the president and lawmakers, said Wednesday he had officially invited Sariyev to join the new Cabinet.
Sariyev said he cannot work in a government which he criticizes for political reasons.
He said the government should be "a team of associates," adding that the new Cabinet and the movement For Reforms cannot be called associates.
Sariyev said he had suggested to the premier that he "begin official consultations with the opposition forces to adjust policies and work out common approaches to Kyrgyzstan's development."
In late January, President Kurmanbek Bakiyev nominated Isabekov, then serving as agriculture minister, after MPs twice rejected the candidacy of former premier Felix Kulov, who resigned late last year after mass protests in the impoverished ex-Soviet state that forced through a series of amendments to the Constitution.