Security concerns and moving battle fronts in southern Afghanistan are severely limiting efforts to aid the local population in the battle-scarred region, a senior United Nations humanitarian official says in Kabul on Wednesday.

"Right now we will have to have to see how the offensive affects the situation but one of our major concerns is that we are already so very restricted and it is very difficult to reach out, to get correct information and to be able to establish a base line to help people," acting U.N. Emergency Relief Coordinator Margareta Wahlstrom told a press conference in Kabul, when asked about a possible spring offensive by the ousted Taliban.

At the same time Wahlstrom, who has spent five days visiting Kabul and Kandahar, said she was "quite impressed by a lot of progress that is visible, things that you can see that look much better including in the south" since her last visit two and half years ago.

"But I think our concern is very much that in order to sustain progress we also need to became much better at covering all parts of Afghanistan with assistance to reach out," she added. "Our concern for the south and other areas that are difficult to access is really to ensure that this lack of access does not undermine progress and the relative stability we have in the rest of the country."

Among the signs of progress, she cited a series of elements, ranging from the removal of all the scrap metal that used to litter Kabul airport and the return of refugees to the capital to road construction, much greater school attendance and a much stronger basic health system.

But she noted that while schools are being built and girls, marginalized by the Taliban regime, are attending class, schools are also being burned down. "This is a sign that should be of great concern to every Afghan, to the Afghan authorities and all the friends of Afghanistan," she added.