The Social Democrat Party's Manuela Schwesig says she is confident of making a full recovery but needs treatment and won't be able to attend every public appointment in the coming months.
Schwesig said Tuesday she plans to give up her position in the center-left party's national leadership but keep her other job as governor of Germany's Mecklenburg-Western Pomerania state.
Schwesig became one of the Social Democrats three interim party leaders following the June resignation of Andrea Nahles. New leadership will be installed in December.
Malu Dreyer, another state governor, will have to lead the Social Democrats alone for a few weeks. The third interim leader, Thorsten Schaefer-Guembel, is joining Germany's international development agency on Oct. 1.