SBU Chief of Staff Oleksandr Tkachuk told Ukrainski Novyny, Censor.NET reports.
"I don't know anyone at the SBU who Savchenko has notified of her plans. By law, she is not obliged to do that, but she should have done it for the sake of elementary security, ordinary human logic," he said.
Tkachuk recalled Savchenko was once captured three years ago in the terrorist-held territory of the Luhansk region and taken to Russia.
"We are surprised by Savchenko's confidence that nothing will happen to her in the "DPR/LPR" territory and the previous scenario won't repeat. Perhaps she knows certain facts that she tells us nothing about, which give her reason to be so sure separatists won't act like before," he said.
The SBU is going to check information about Savchenko's reasons for travelling to occupied Donetsk on Feb. 24.
Earlier, militants of the so-called "Donetsk People's Republic" released information saying that Nadiia Savchenko and Volodymyr Ruban, the head of Officers Corps NGO engaged in the hostage liberation process, arrived in the occupied part of the Donetsk region.
On Jan.10, Nadiia Savchenko published lists of Ukrainian fighters captured or missing in the Donetsk and Luhansk regions and Russian-backed separatists held in government-controlled territory - 524 persons in total. On Jan. 16, Savchenko published updated lists of Ukrainian POWs and captured separatists.
The SBU had opposed the Savchenko's move even before the publication of the lists and promised to talk to her on the issue.
On Dec. 7, 2016, Savchenko secretly visited Minsk to meet with "DPR/LPR" leaders Alexander Zakharchenko and Igor Plotnitsky. The Security Service of Ukraine said this meeting was not agreed. Savchenko was summoned for questioning to the SBU, where she confirmed the fact of negotiations.
On Dec. 12, Savchenko said the meeting was held in the "trilateral Minsk format" in the presence of Russia's representatives, as well as "DPR" and "LPR" leaders Zakharchenko and Plotnitsky.
"I saw smart and sober people who are tired of war and deceived by Russia," Savchenko shared her feelings about the meeting later in Germany.
"LPR" leader Plotnitsky said Savchenko was a "voice" of the self-proclaimed republics in the Verkhovna Rada. After that, Savchenko was excluded from Batkivshchyna and the PACE delegation.
On Dec. 29, Savchenko announced her plans to again meet with Zakharchenko and Plotnitsky: "We can meet in Luhansk, Donetsk and then in Kyiv."