Ukrainian President Viktor Yanukovich has announced an agreement to hold presidential elections early, form a national unity government and make constitutional changes reducing his powers.
He made the announcement in a statement after all-night talks with the opposition and three European Union ministers on resolving a crisis in which at least people were killed in two days of gun battles between protesters and police.
There was no immediate confirmation, however, from the opposition that it would accept the plan and call off protests.
Al Jazeera's Andrew Simmons, reporting from the capital Kiev, said the opposition was still conferrring with its supporters on whether to accept the terms of the deal.
Al Jazeera's correspondent said that Yanukovich had been steadily losing power ahead of the announcement.
"Unless he's prepared to stand down, this deal, if there is one and it goes through, will not succeed. [The opposition] expect nothing more than the departure of the president," Simmons said.
The opposition and EU ministers did not immediately confirm agreement had been reached and diplomatic sources said the talks had been "very difficult".
Fighting broke out between deputies in the parliament later on Friday when the speaker declared a pause, delaying a debate on a possible resolution calling for Yanukovich's powers to be reduced.
Several deputies exchanged blows as chaos descended on the chamber for several minutes. The speaker, Yanukovich ally Volodymyr Rybak, then left the chamber but some of the deputies continued the debate.
Back on the streets, a shaky peace reigned in the protest camps in downtown Kiev from Friday morning after days of fighting left at least 75 people dead.
Yanukovich was expected to "make concessions in order to restore peace", Interfax Ukraine news agency had quoted his spokeswoman Anna German as saying.
Support for the president had appeared to be weakening, as reports said the army's deputy chief of staff, Yury Dumansky, was resigning in "disagreement with the politics of pulling the armed forces into an internal civil conflict".
Late on Thursday, the Ukrainian parliament passed a measure that would prohibit an "anti-terrorist operation" threatened by Yanukovich to restore order, and called for all interior ministry troops to return to their bases.
But it was unclear how binding the move would be, as the mechanism for carrying it out would have to be developed by the president's office and the interior ministry.
On Friday morning, several thousand protesters milled around Independence Square, known as the Maidan, which earlier this week was rocked by street battles between protesters and police.
No visible police forces remained on the square, and volunteers walked freely to the protest camps to donate food and other packages.
Yanukovich and the opposition protesters are locked in a battle over the identity of Ukraine, a nation of 46 million that has divided loyalties between Russia and the West.
Parts of the country - mostly in its western cities - are in open revolt against Yanukovich's central government, while many in eastern Ukraine back the president and favour strong ties with Russia, their former Soviet ruler.