Mir - the space station that will fall to earth
The official, Yuri Semyonov, who heads the corporation which owns Mir, said a Progress cargo spacecraft will give Mir a downward push and it will eventually fall to Earth.
But a Russian Space Agency spokesman, Sergei Gorbunov, said it is not exactly clear if or when this will happen.
"The final decision to end Mir's mission has not yet been approved," Mr Gorbunov said.
The United States has urged Moscow to retire the 124-tonne Mir station, which has been plagued by a series of technical failures.
The move will allow Russia to devote its energies and finances to a new international space station due for launch later in 1998.
Mir's lowering process is expected to take about eight months and will involve the launch of between two and four cargo craft to push it in the right direction.
"During this period Mir will be lowered to 130 km above the Earth," said Mr Gorbunov, adding that the cosmonauts would leave the station at a safe altitude, about 150 km.
The Space Agency says Mir would eventually burn up in Earth's upper atmosphere, although parts may fall in the ocean.
Mir consists of five modules where cosmonauts live, work and carry out experiments.
Two Russians and one American are now on board, the latest of more than 100 cosmonauts and astronauts to visit Mir.