David Miliband has been meeting other EU ministers to talk about Afghanistan
Foreign Secretary David Miliband has said that the UK, the US and their allies face a "strategic stalemate" in some parts of Afghanistan.
He said a "bigger and more effective" security force was needed to stop the Taleban controlling more territory.
Mr Miliband said some EU countries should provide more troops and carry a "better share of the burden."
He was speaking as British and European leaders await President Obama's review of Afghan policy, due next week.
Mr Miliband told the BBC: "In parts of the country there is a strategic stalemate.
"It is not true that the Taleban are overwhelming our forces because in any conventional encounter they lose.
"But they are a terrorist insurgency force which is able to do grave and grievous damage to our own troops and others."
The foreign secretary has been attending a summit in Brussels where he and other EU ministers backed a plan to send more police to train local officers in Afghanistan.
But while Mr Miliband praised the contribution of Denmark and the Netherlands, he said the burden of fighting in Afghanistan should be shared more equally by other EU countries.
He said: "Some countries are doing significant amounts but other countries have got either significant caveats on the deployment of their troops or they've got their troops in parts of the country where there isn't the same level of insurgency.
"We do want a better sharing of the burden; however, it's not the case that we're the only people there."
Mr Miliband met the US Secretary of State, Hillary Clinton, on Wednesday to discuss the imminent US review of policy in Afghanistan.
Among the recommendations President Obama is expected to support is a 17,000 increase in the number of US troops and more civilian experts - such as agronomists - to help rebuild the Afghan economy.