German Defence Minister Thomas de Maiziere, a close ally of Chancellor Angela Merkel, admitted mistakes on Monday, June 10 in his handling of a botched deal for reconnaissance drones but said these shortcomings were no reason to resign, Reuters reported.

The minister has come under pressure since cancelling plans to purchase four costly Euro Hawk drones last month. The center-left opposition has seized on a topic it hopes will damage Merkel three months before a federal election.

In a hastily arranged news conference, de Maiziere, defense minister since March 2011, rejected charges that he had given misleading statements over what he knew when and said he had always been told problems with the drones could be solved.

"In retrospect, I must say that when I heard about the 'solvable problems' I waited too long. I should have asked questions, and requested a report about the scale of the problems and how they would be rectified," he said.

He pulled the plug on the planes made by EADS and Northrop Grumman after it became clear it would cost too much to ensure they met required flight safety standards.

Merkel has watched a series of aides be forced out of office in recent years, leaving her vulnerable to accusations of being a poor judge of character.

In February confidante Annette Schavan quit as education minister after being stripped of her doctorate for plagiarism. Last year, Merkel's hand-picked choice for German president, Christian Wulff, resigned in disgrace over financial favors.