RUSSIA'S Prime Minister has pledged to boost the country's military might, amid growing signs that he could emerge as President Vladimir Putin's successor next year.

Viktor Zubkov, an old friend of the President who served as a low-profile bureaucrat until his recent dramatic elevation, spoke as British and Norwegian jets were again scrambled after two Russian bombers probed NATO air space in the latest of a spate of such incidents in the past two months.

Mr Zubkov, whose new position has been approved by Russia's rubber-stamp Parliament, becomes the first Kremlin heavyweight to declare an interest in contesting presidential elections in March. Mr Putin is constitutionally obliged to step down and Mr Zubkov seemed to win the President's support for his bid.