Foreign Secretary William Hague warned Cabinet colleagues today that Britain and its allies must prepare for the long haul in Libya as weeks of air strikes show little sign of unseating Muammar Gaddafi.
Mr Hague was updating Cabinet as Defence Secretary Liam Fox flew to the US for talks on the best way of stepping up pressure on the Libyan dictator's forces.
The Foreign Secretary insisted that there were "grounds for optimism", 38 days after international military action was launched to enforce United Nations (UN) Security Council resolution 1973.
Summarising Mr Hague's comments to Cabinet, a Downing Street spokeswoman said: "The general tone was that there were grounds for optimism, good progress was being made, the alliance was holding up very well, but clearly we need to turn up the pressure.
"The mission is going in the right direction but we need to prepare for the long haul."
Recent signs of progress included the US decision to deploy unmanned Predator drones, Italy's provision of jets for allied bombing sorties and the introduction of mentors from the UK, France and Italy to advise the opposition interim transitional national council, which was stepping up its contacts with the outside world.
Gaddafi was being put "under increasing pressure" but it was "sensible planning" for the allies to prepare for the mission to continue for a long haul, said the spokeswoman.
"No-one has been able to put a date on when this will finish," she said. "What is important is that we implement the UN Security Council resolution (UNSCR).
"Naturally we want to see a rapid conclusion, however, we have to be prepared for whatever it takes in order to enforce UNSCR 1973."
Dr Fox will speak to US counterpart Robert Gates during today's visit while Chief of the Defence Staff General Sir David Richards will also speak to his opposite number.
Before flying to Washington, Dr Fox told the Daily Mail: "If the regime continues to wage war on its people, those who are involved in those command-and-control assets need to recognise that we regard them as legitimate targets.
"Those who are in command-and-control assets, controlling the regime's activities against its own people, would have to recognise the risks they would have if they were there during Nato strikes."
The Ministry of Defence today released details of UK involvement in Nato's military operations in Libya over the Easter weekend.
The Chief of Defence Staff's spokesman Major General John Lorimer said: "UK forces have continued to make a major contribution over the weekend to Nato's Operation Unified Protector to protect Libyan civilians under threat of attack and to enforce United Nations Security Council resolution 1973.
"Coalition air patrols have continued to focus on the areas around Misrata, Brega and Ajdabiya, and Yafran.
"On Saturday, RAF Tornado and Typhoon aircraft successfully attacked three armoured personnel carriers near Misrata, as well as a surface-to-surface missile facility near the city. Eight rocket launcher vehicles were seriously damaged and eight support vehicles are assessed to have been destroyed.
"RAF aircraft returned to the same missile facility on Sunday and destroyed rocket-storage facilities, as well as a main battle tank nearby.
"On Monday, UK aircraft engaged a tank near Mizdah and a self-propelled gun near Yafran as well as a number of missile launchers south-west of Misrata."Reuse content