Sleepless and exhausted, they shook each other's hands and then huddled to confer with their own groups. Then, wearily, they made their way to the microphone on the dusty stretch of ground outside, lit by the dull orange glow of spotlights. As 100 flashbulbs went off they told the international media that they had failed to break the deadlock. Peace in Kosovo was not to be achieved that morning.
Both sides, predictably, blamed each other. Lieutenant General Sir Mike Jackson, the British commander of Nato's Kosovo force, said the Yugoslavs had failed to live up to the conditions of the recently brokered peace deal. Their terms did not guarantee the safety of refugees going home, and did not provide for a full withdrawal from Kosovo.
The Yugoslav Assistant Foreign Minister, Nehojsa Vujovic, protested that they had come to talk in good faith; Nato's demands were unreasonable; and the only way forward was through a UN resolution.
Yesterday, details of what went wrong at the talks at Kumanovo airfield was starting to emerge. It painted a picture of intrigue, realpolitik and mendacity. It also raised questions about just what role the Russians had played in the affair.
At the airfield, a huge camouflage tent was cleared for the talks and air-conditioning was installed overnight. Maps and charts, faxes and satellite phones were all in place.
The Yugoslav delegation arrived early, with Colonel General Marjanovic leading the way. They almost bounced into the tent and professed their willingness to be as helpful as possible over the teas, coffees and biscuits.
The talks started almost at once. The tent was soon a hive of activity with little groups clustered around maps and charts, planning routes, debating logistical difficulties.
British, French, Germans and Italians mixed with the Serbs to attempt to work out how the Yugoslav forces could withdraw from Kosovo within a prescribed time frame.
One Nato official recalled: "They were not only amenable to ideas, they were putting forward some useful ones of their own."
The only irritant was the noise caused by the air-conditioning, and it was switched off.
As the media waited outside in the heat, expecting the announcement of an agreement within hours, the parties inside worked through their lunch. It was provided by the French - quiche, salad, grapefruit and creme brulee.
Then, suddenly, the mood changed. Colonel General Marjanovic began to show the toughness which had allowed him to prosper in the Yugoslav army. The objections to Nato plans began. Asking for a 25km demilitarised zone inside the Serbian territory was an infringement of the nation's sovereignty: the Serbian army could not be expected to clear their own minefields: the time limit for the withdrawal of heavy armour was unrealistic.
And then came two totally unexpected demands: that Nato bombing should stop even before the terms of withdrawal of Serbian forces had been agreed, and the whole matter should take place under a United Nations resolution.
General Jackson and his colleagues pointed out that these were political questions which had already been settled when the Yugoslav government ratified the plan put forward by Russia's Balkan envoy, Viktor Chernomyrdin, and President Martti Ahtisaari of Finland. But the Yugoslav delegations were insistent that this must now form part of the talks.
At that point a flurry of phone calls began. From the Nato delegation to Supreme Allied Commander Wesley Clark, to the Nato secretary-general, Javier Solana, and the British and American governments. From the Serbs back to their chief of defence staff, Dragojlius Ojdanic, who had felt it prudent not to attend as he was wanted by the international war crimes tribunal in The Hague, and also the Milosevic government.
Late in the afternoon there suddenly appeared the Russian military attache to Belgrade, Lieutenant General Yvgeny Nikolaivic Barmijancev. He was soon in hurried consultations with the Yugoslavs. Nato officials felt that this could lead to a breakthrough.
However, if the Russian general was trying to soften the Serbian position it appeared to have the effect of hardening it.
A break took place at 5.30pm for the Serbians to consult Belgrade yet again. They were due to return at 9pm but asked for an extension. When they did come back, just before midnight, nothing appeared to have changed. The Security Council resolution had become paramount, and also the demand for a halt to Nato air strikes before constructive dialogues could take place.
Among Nato officials there was barely suppressed fury. Two long days of negotiations appeared to have been wasted. The talks went on desultorily for a few more hours at a lower level before meandering away to a close.
One Nato official said yesterday morning: "We were exhausted but determined to try and achieve something. But the Serbian position made this impossible.
"We shall continue a dialogue with face-to-face meetings on informal levels, but the chance for peace has gone back a long way."