Whatever the joint working group signs, I will agree with it

Ukrainian President Leonid Kuchma

On Tuesday, the inquiry team said fragments had been found in the plane wreckage which were "very similar" to parts of an S-200 missile - the type being test-fired by Ukraine at the time.

Immediately after the crash, Ukraine vehemently denied that its military exercises were responsible, but officials have this week released information showing that one of its missiles fell closer to the crash site than previously admitted.

The BBC's Russian affairs analyst, Stephen Dalziel, says Mr Kuchma's latest comment indicates he is paving the way for a belated admission of responsibility.

Air defence envoy

"Whatever the joint working group signs, I will agree with it," Mr Kuchma said.

"We should not make a tragedy out of matters if it was a mistake. Bigger mistakes have been made," he added.

Investigators say holes in wreckage are consistent with missile damage

The head of Ukraine's air defence forces, Volodymyr Tkachov, was despatched to Sochi, near the crash site, following the news that investigators had found the scraps of missile amongst the wreckage.

The missile is designed to fragment just short of its target, blasting the object with shrapnel.

The Tu-154 airliner came down about 250km (156 miles) from land with the loss of all 78 crew and passengers. It was on a flight from Tel Aviv to Novosibirsk in Siberia.

'Out of range'

"We have found a lot of material which allows us to expect that in time the 'missile' theory will become dominant in the investigation of the crash of the Tu-154 plane," said Yevgeny Shaposhnikov, a member of the investigating commission.

The Ukrainians have confirmed that one of their missiles fired from the Crimean Peninsula had travelled 80km (50 miles) from its launch site, and came down in the Black Sea - 40km (25 miles) further than previously admitted.

But they still insist that the missile fell well short of the crash site, and would not have had the capability of travelling that far.

Ukrainian Defence Minister Oleksandr Kuzmuk said an S-200 was fired 10 minutes before the plane would have crossed its trajectory.

He said the missile had fallen into the sea two minutes before the plane disappeared from the radar, and that the distance between the plane and the launch site was about 270km (168 miles) - further than the missile's range.

However, other military sources believe the missile could have reached the plane in the upper limit of its range.

Early in the inquiry, a mechanical fault or terrorist attack had been considered possible explanations for the crash, though these have faded from view as evidence for a stray missile has mounted.

Our analyst says Mr Kuchma is now preparing Ukraine for the worst.