By Angela Dewan and Judith Vonberg, CNN

(CNN) -- A Russian journalist and Kremlin critic, reported to have been shot dead in Ukraine, has appeared alive at a news conference and declared that his murder was faked by Ukrainian security services to foil an assassination plot against him.

Arkady Babchenko was said to have been killed in his apartment building in the Ukrainian capital Kiev Tuesday. Ukraine blamed Russia for his "death."

But in a stunning development, he appeared alongside Ukrainian security officials in a news conference broadcast live on Ukrainian television Wednesday afternoon.

Ukraine's Security Service said it had staged the murder in an attempt to foil a Russian plot to kill Babchenko. The Chief of the Security Service of Ukraine (SBU), Vasyl Hrytsak, said the operation had been planned for two months.

Writing on Twitter, the security service said it decided to conduct the operation to collect evidence of terrorist activity by the Russian special services on Ukrainian territory.

On Tuesday, Ukrainian state news agency Ukrinform had said that Babchenko, 41, was shot in the back and died in an ambulance, citing his friend and supervisor, Ayder Muzhdabaev, deputy general manager of Ukrainian TV channel ATR. Police in Kiev said Babchenko's wife found him outside their apartment.

The Ukrainian police said they were searching for the man they believed to be responsible for the assassination and even released a sketch of the suspected killer.

During the news conference Wednesday, Babchenko apologized to his wife and all those who believed he had been killed -- but said the secrecy had been unavoidable.

"I would like to apologize for what you all had to go through... because I've buried friends and colleagues many times, and I know it's a sickening-vomiting feeling when you have to bury your colleagues," he said. "Also I would like to apologize to my wife for the hell she went through in those two days. Olechka, I'm sorry, but there were no options here either."

He also thanked the Ukrainian security services for saving his life.

Ukraine-Russia tensions

Shortly after Babchenko's death was announced, Moscow and Kiev began blaming each other for the killing of the journalist, who is a vocal critic of the Kremlin and left Russia in 2017, saying he no longer felt safe.

Ukrainian Prime Minister Volodymyr Groysman implied Russia had orchestrated the "killing" of Babchenko, while Kremlin spokesman Dmitry Peskov dismissed that idea and slammed Ukraine as an unsafe place for journalists to work.

On Wednesday Russian foreign ministry spokeswoman Maria Zakharova said the affair was a propaganda exercise by Ukraine, but that she was happy Babchenko was alive.

Babchenko left Russia after he criticized the Kremlin in a Facebook post in 2017.

He faced backlash after commenting on the crash of a Russian plane transporting the world-famous military choir Alexandrov Ensemble en route to Syria. They were traveling to perform for pilots involved in Russia's air campaign on Aleppo.

Babchenko called Russia an aggressor, and accused the country of killing children in its air support of Syrian President Bashar al-Assad's regime.