FRANKFURT - Euro zone inflation is stubbornly high so the European Central Bank must also be tenacious in fighting it, ECB policymaker Joachim Nagel said on Friday, remaining non-committal about the bank's next move in September.

"We need interest rates to be high enough and we need to keep them there for as long as necessary," Nagel, who heads Germany's Bundesbank, said in a statement. "Core inflation is stubborn, so our monetary policy needs to be even more tenacious."

Nagel earlier said he was not convinced ECB rates would peak before the summer break but he did not repeat such comments on Friday.

(Reporting by Balazs Koranyi; Editing by Francesco Canepa)