German Defence Minister Christine Lambrecht resigned from Chancellor Olaf Scholz’s government on Monday, the culmination of growing doubt about her ability to revive Germany’s armed forces against the backdrop of the Ukraine war.

Her decision dealt a blow to Scholz at a time when Germany is under pressure to approve an increase in international military support for Kyiv, and Germany’s defence capabilities have been called into question after several Puma infantry tanks were put out of service during a recent military drill.

The pressure to find a successor is mounting also because U.S. Secretary of Defense Lloyd Austin is expected in Berlin on Thursday and will attend a conference on Friday at the U.S. military base in Ramstein, in the state of Rhineland-Palatinate, to discuss further support for Ukraine, including whether to send German-built battle tanks.

Lambrecht asked Scholz to dismiss her, as formally required, and he has approved, a spokesperson for the Social Democratic (SPD)-led coalition government said.

During a visit to arms manufacturer Hensoldt, Scholz thanked Lambrecht for her service and said he would act fast to replace her. “I have a clear idea and it will be known very quickly for everyone how this should proceed,” he told reporters.