NEW DELHI - Even as controversy still rages over the Bush administration's plan to divert over $250 million in aid to Pakistan from counter-terrorism programmes to upgrading its F-16 fighter jets, the US has now invited the Pakistani Air Force (PAF) to take part in its world-famous 'Red Flag' wargames, reports The Times of India. "The US has apparently asked Pakistan whether it will be willing to participate in the Red Flag exercise in 2009. Pakistan's response is not yet known," said a senior official. The US invite to PAF, incidentally, comes soon after the return of the Indian Sukhoi-30MKI fighters, IL-78 mid-air refuellers and IL-76 heavy-lift aircraft from the Red Flag exercise held at the Nellis US Air Force base at Nevada in August.  The Red Flag invite is being seen as "a balancing act", the Indian security establishment is more "concerned" about the continuing US military aid to Pakistan on the pretext of helping it fight terrorism. The Bush administration holds the upgraded F-16s will support Pakistani Army's operations against militants along the volatile Pak-Afghan border and the Federally Administered Tribal Areas. Once upgraded with advanced targeting pods, radar systems, precision-guided munitions and missiles, the Pakistani F-16s will be able to undertake night precision-bombing missions and close-air support operations. Interestingly, this comes at a time when some amount of brinkmanship is taking place between US and Pakistani forces along the Pak-Afghan border, with US President George Bush even authorising cross-border ground assault operations without prior approval by Islamabad. Along with the upgrade packages for Pakistani F-16s, Cobra helicopters and other platforms, the US will also train PAF in close-air support, aerial refuelling and night-flying operations, with the Red Flag exercise dovetailing into these plans. All this is bound to raise concern in India, especially since Pakistani F-16s are also jury-rigged to deliver nuclear weapons. Moreover, Pakistan is now also gearing up to induct the first lot of the planned 250 JF-17 'Thunder' fighters from China.