A convoy of 280 Russian trucks headed for Ukraine

 A convoy of 280 Russian trucks headed for Ukraine, which Moscow says is carrying relief goods for war-weary civilians, has suddenly changed course, according to a Ukrainian state news agency.

With thousands of Russian troops still posted near the Ukrainian border and Ukraine's military putting increasing pressure on pro-Russian fighters around the city of Donetsk, many in Ukraine and elsewhere fear that the so-called humanitarian mission is actually an attempt to smuggle supplies to pro-Russian rebels.

"Russia keeps inventing new excuses for their policy," Ukraine's deputy foreign minister, Danylo Lubkivsky, said Tuesday in Kiev. "In Georgia, it was defending pro-Russian minorities. In Ukraine's Crimea, preventing NATO invasion."

The International Committee of the Red Cross contacted the aid convoy in the Rostov region, the organization said Thursday via Twitter. The group said it would discuss with Ukrainian officials how the operation will be conducted.

The convoy was seen earlier in the day 25 miles from the Ukrainian border in the Rostov region, according to video shot and distributed by Reuters.

If the trucks cross the border and before they reach the area controlled by separatists, they would have to be examined by Ukrainian border guards, a Ukrainian security official said.

At that point, the convoy would be handed over to Red Cross representatives, the official said.

The office of the Ukrainian counterterrorism operation said Thursday it could not confirm that the convoy has crossed on the Ukrainian side. The Ukrainian border service denied reports that the convoy had crossed from Russia.

"All responsibility for the safety of this convoy lays with Russia because it is controlling armed mercenaries there," Ukrainian national security and defense council spokesman Andeiy Lysenko told reporters in Kiev.

The trucks had been expected to arrive at a checkpoint in Kharkiv on Wednesday but bypassed that route, according to the website Ukrinform. It's not clear what route the convoy will now take.