``He knows the direction he has to move in if he wants to avert airstrikes,'' said a NATO official after the 16 ambassadors were briefed on 16 hours of weekend talks between Milosevic and the two top alliance generals.

British foreign secretary Robin Cook said in Luxembourg said that if Milosevic sticks to the deal ``that will certainly be a significant advance, but we want to see the evidence first.''

Intelligence reports today showed that ``there is some indication some units are regrouping for withdrawal,'' said the NATO official. He said NATO remained resolved to use military force once a deadline on withdrawal runs out at 8 pm (12.30 pm IST) on Tuesday. ``He has to get his skates on for the next 24 hours,'' the officials said.

Milosevic ``agreed in very detailedterms to the withdrawals'' during talks with NATO generals Wesley Clark of the United States and German general Klaus Naumann. The generals were in Belgrade over the weekend to reinforce a strong letter from NATO secretary-general Javier Solana, stressing the alliance would not hesitate to use military action if necessary.

``The planes are still on the runway. If Milosevic does not want them to take off then it is up to him to comply, he knows what he has got to do,'' said Cook ahead of a meeting of EU foreign ministers.

NATO will assess the level of withdrawal tomorrow afternoon before a NATO council will meet just hours before the deadline expires.