Relatives of the victims, which included 45 children under 12, are due to fly out from Pulkovo airport in Saint Petersburg to the scene of the crash 45 kilometres north of Donetsk.
Russian Transport Minister Igor Levitin was among the senior officials who travelled to the crash site to oversee recovery and investigation efforts.
Officials quoted by Ukrainian media said so far only 30 bodies had been recovered. Wreckage however was scattered over a wide area, where plane parts and the surrounding land were scorched.
Russian President Vladimir Putin and his Ukrainian counterpart Viktor Yushchenko spoke about the crash on Tuesday and have declared days of mourning in Ukraine on Wednesday and in Russia on Thursday.
"In the name of all the Ukrainian people, President Viktor Yushchenko expressed his sincerest condolences to Russian President Vladimir Putin," Yushchenko's office said in a statement.
The plane, a Tupolev-154 jet owned by Russia's Pulkovo airlines, was on a flight from the Russian Black Sea coast city of Anapa to Saint Petersburg when it ran into severe weather, officials said.
It was flying at an altitude of 10,000 metres when it was forced to make an emergency landing. Ukrainian officials said the crew had declared a fire on board before the plane went down.
Both Russian and Ukrainian aviation authorities said severe high-altitude weather with driving rain, fierce winds and lightning appeared to have been a decisive factor in the crash.
Irina Andrinovna, spokeswoman for Russia's emergency situations ministry, was quoted by Interfax Tuesday as saying that the crash occurred "as the result of a lightning strike as the plane flew into a storm front."
Igor Krol, a spokesman for the Ukrainian emergency situations ministry, said the plane's landing gear then failed to deploy normally and the aircraft crashed "on its belly."
Russian Prosecutor General Yury Chaika has announced the opening of a criminal inquiry into a possible "violation of safety rules”.
Vasily Nalyotenko, deputy head of Pulkovo, the main airport in Saint Petersburg, said the plane, built in 1992, had flown 24,215 hours and conformed fully to safety regulations.
At the site of the crash, wreckage was scattered over marshlands where the plane went down and a large part of the surrounding area was burned. The area was cordoned off.
The plane, a tri-engine jet similar in size and construction to a Boeing 727, can carry around 180 passengers and has been used as a workhorse of civil aviation fleets in Russia and other former Soviet states.
Anapa, located along the same stretch of Black Sea coast as the better-known resort city Sochi, is a popular holiday destination for many Russians.