LONDON, July 15 (UPI) -- Britain is sending four more Tornado warplanes over Libya to support NATO military operations as an international contact group explores ways of ending the stalemate pitting the U.N.-backed armed rebels against loyalist forces of Moammar Gadhafi.
The military measures were announced amid intensive mediation at different levels on securing an end to five months of an inconclusive campaign in support of the rebels' Transitional National Council.
The council received formal support from the contact group of NATO and Arab diplomats meeting in Istanbul but China and Russia stayed away.
The rebels are receiving weapons and ammunition from France, logistical and medical support from Britain and substantial quantities of unspecified weapons and backup operations from Qatar and other Arab countries.
British military experts are helping rebels in and around Benghazi and other British teams of mostly undercover special agents are reportedly on the ground but not acknowledged in official reports.
The dispatch of the additional four British air force Tornado warplanes takes to 16 the total number of the attack and surveillance aircraft active over Libya. British officials have said the Tornado's 3,000-mile missions to carry out attacks on Libyan military sites were the longest range bombing missions conducted by the air force since the Falkland Islands conflict with Argentina in 1982.
British air support for the Libyan rebels has also included laser-guided bombs, deployed with the LITENING targeting pod, and Brimstone missiles.
British Foreign Office Minister Alistair Burt said the aircraft were well-equipped for surveillance and reconnaissance.
"It is important to have this capability available," he said.
The British announcement followed a plea from NATO Secretary-General Anders Fogh Rasmussen for more aircraft to support operations protecting Libyan civilians against government forces' assaults on rebel-held communities.
NATO warplanes have conducted more than 5,000 air missions since the action began in March, officials said.
European concerns over the escalating costs of the military operations in Libya resurfaced at the Istanbul meeting. However, diplomatic analysts suggest some of the costs could be defrayed by NATO accessing Libyan state funds frozen at the start of the crisis.
Turkish Foreign Minister Ahmet Davutoglu said at least $3 billion could be released to cover the cost of humanitarian assistance to tens of thousands of Libyans displaced by the conflict or trapped in battle zones.
The actual NATO costs in Libya are mired in mystery amid conflicting statements, some designed to deflect public criticism of the campaign.
British Prime Minister David Cameron, frequently queried over the British spending, has yet to give any updated total after early reports that about $40 million-$50 million was spent. Chancellor of the Exchequer George Osborne said British operational costs in Libya were "tens rather than hundreds of millions" of dollars.
NATO Supreme Allied Commander U.S. Navy Adm. James Stavridis told the U.S. Senate "hundreds of millions" could already have been spent in the NATO operation.
U.S. officials said the military intervention cost the Pentagon alone at least $608 million in bombs, missiles and logistics. Pentagon estimates set the monthly cost of the air campaign to the United States alone at $40 million.
French military costs in Libya were estimated by Parisian defense analysts at more than $600 million.