Ukrainian President Petro Poroshenko Thursday accepted the resignation of the country's top security official, the presidential press service said.
Earlier in the day, Andriy Parubiy, secretary of the National Security and Defense Council (NSDC), announced his decision to resign without revealing the reason behind the move, Xinhua reported.
"I resigned from the post of the NSDC secretary. During the war, I consider it inappropriate to comment on the reasons for the resignation," Parubiy wrote on his official Facebook page.
Parubiy, 43, took charge of the NSDC, which supervises the defence ministry and the armed forces, in February after the downfall of former president Viktor Yanukovych's government.
From last November through February, he was an active participant and senior coordinator of protests against Yanukovych and his government.