Defence Secretary Liam Fox has called for a renewed effort to free the Libyan people from "the excesses of the Gaddafi regime".
He said there should be a sense of greater urgency "in some quarters" as the campaign enters its second month since the start of military operations to protect civilians from attack.
Mr Fox was attending talks with fellow Nato defence ministers to review the allied effort.
Nato has just extended its Libyan mission by 90 days to intensify military pressure on Colonel Gaddafi. Nato Secretary General Anders Fogh Rasmussen, chairing talks on the next steps, explained previously: "We are determined to continue our operation for as long as it takes."
He said this latest meeting was to "take stock of the progress we have made and to look ahead. I expect us to begin discussing how we prepare for the day after Gaddafi goes, because that day is coming".
Mr Fox made clear at the meeting that the UK was at the forefront of the action - but others could do more: "The United Kingdom has been very forward-leading, very clear that we want to see the Libyan people safe from the excesses of the Gaddafi regime."
Earlier, he commented: "We want to see increased urgency in some quarters in terms of Libya."
Mr Rasmussen is looking for bigger commitments to the combined air action, just as the bombing of Tripoli reaches a new intensity. He is also pressing more Nato allies to play an active role, insisting that the mission has already "seriously degraded the ability of the Gaddafi regime to attack civilians".
He described Colonel Gaddafi as "part of Libya's past", adding: "The future belongs to the people of Libya."
Mr Rasmussen was not only seeking increased military contributions from allies who have so far taken a back seat but also "more flexible" use of equipment already being deployed for the operation.