Voser was speaking at a news conference in Ankara with Turkish Energy Minister Taner Yildiz. Voser was also set to meet Turkey's Prime Minister Tayyip Erdogan.

Last November, TPAO signed an accord with Shell for hydrocarbon exploration and production in the Mediterranean and southeastern Turkey.

That agreement included plans for shale gas exploration near the southeastern city of Diyarbakir and Yildiz said Shell had started exploration at the Saribugday 1 field there last week.

TPAO said previously it would take a 70 percent share of production at Diyarbakir, with Shell taking 30 percent.

Voser also said Shell was on track to start exploring for oil in Alaska after receiving the green light there.

The Environmental Protection Agency said last week Shell, which has spent about $4.5 billion on its effort to drill Arctic oil, would soon get a temporary air permit to operate a drilling rig offshore Alaska.

"Last week we received the go ahead to start drilling preparations in Alaska. Therefore we are looking forward to further progress in drilling activities in Alaska," Voser said.

"We are on track to deliver that," he added, referring to drilling activities at two wells.

(Reporting by Orhan Coskun, Writing by Daren Butler; Editing by Nick Tattersall)

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