Horst Seehofer, the leader of one of Germany's governing parties and Chancellor Angela Merkel's most prominent domestic critic during the migrant crisis, says he plans to stay on beyond 2018 — reversing previous statements that he would step down.

The 67-year-old Seehofer has been Bavaria's governor and leader of the Christian Social Union since 2008. The CSU is the Bavaria-only sister to Merkel's Christian Democratic Union. It's an important source of conservative votes but an often-awkward ally.

Seehofer once threatened Merkel's federal government with a lawsuit over the migrant influx and has pushed for a cap on the number of asylum-seekers that Germany accepts. But he has since thrown his weight behind Merkel's quest for a fourth term.

Seehofer said Monday he will seek new terms as governor and CSU leader.