Ukrainian president Viktor Yanukovich has unexpectedly gone on sick leave after a bruising session of parliament, leaving a political vacuum in a country destabilised by anti-government protests.
The 63-year-old president has appeared increasingly isolated in a crisis born out of a tug-of-war between the West and Ukraine's former Soviet overlord Russia, Reuters reports.
Shortly after his office announced he was suffering from an acute respiratory ailment, he defended his record in handling the crisis and accused the opposition, which has called for his resignation, of whipping up the situation.
"We have fulfilled all the obligations which the authorities took on themselves," he said, referring to a bill passed late on Wednesday granting a conditional amnesty for activists who had been detained.
"However, the opposition continues to whip up the situation, calling on people to stand in the cold for the sake of the political ambitions of a few leaders. I think this is wrong," the presidential statement said.
The amnesty offered freedom from prosecution to peaceful protesters, but only on condition that activists left official buildings they have occupied - something they have rejected.
Prime Minister Mykola Azarov resigned earlier this week after a sharp escalation of the street unrest that began in November over Mr Yanukovich's rejection of a European Union deal in favour of closer ties and a bailout deal with Russia.
The president, under pressure from Moscow not to tilt policy back towards the West, has yet to appoint a successor. Serhiy Arbuzov, Azarov's first deputy and a close family friend of Yanukovich, has stepped in as interim prime minister.
A statement on the presidential website gave no indication of when he might be back at his desk or able to appoint a new government, which Moscow says must be in place before it goes ahead with a planned purchase of $2 billion of Ukrainian government bonds.
Six people have been killed and hundreds injured in street battles between anti-government demonstrators and police which escalated sharply after the authorities toughened their response. A seventh person, a police officer, died of a heart attack on the street on Wednesday night.