By Matthew Price BBC reporter in the Balkans

The UN mission in Bosnia says no contingency plans are being made to withdraw personnel following the failure of the United Nations Security Council to renew its mandate in the country for the next six months.

The United States has vetoed a resolution to extend UN peacekeeping operations in Bosnia because it did not win agreement to exempt US peacekeepers from prosecution by a new international war crimes court.

Representatives in Bosnia say a withdrawal is unlikely

Council members briefly extended the mandate for 72 hours in order to try to resolve the dispute

Bosnia's peacekeepers must now wait as the clock ticks on a deadline to renew their mandate to operate in the country.

There are 1,500 police officers and hundreds of logistical staff who, if no agreement can be found, will have to start packing their bags on Thursday.

No panic

Officially there does not appear to be any panic among UN staff.

A spokesperson told the BBC that they are simply waiting to see what happens.

For the time being, she said, we are optimistic.

UN peacekeeping force in Bosnia

Established in 1995 to promote regional stability Includes police officers from 43 countries Made up of 1,539 officers, 46 from the United States Led by UN High Representative Paddy Ashdown Due to relinquish control to an EU mission in 6 months

This mission is far too important, she added, for an agreement not to be found.

At the office of the High Representative for Bosnia, Lord Paddy Ashdown, a spokesperson said that "the reasonable person's assumption" was that a withdrawal was not going to happen.

If it does, however, it would be a massive logistical exercise.

The UN role is essentially a policing one.

At the moment its staff are training a new Bosnian police force and at the end of the year the UN is due to hand over to European officers.

But that was to be a controlled, planned exercise.

Any sudden change in the timetable would be, in the words of one spokesperson, a huge dislocation.

There is also a question-mark hanging over the status of the Nato-led peacekeeping mission in Bosnia, S-for, which includes US officers.

It's unclear whether a new mandate would have to be negotiated, but as was recently shown in Afghanistan, that can be done.