The president of Ukraine and the leader of the anti-government movement have agreed to a "truce" and "negotiations" aimed at bringing an end to the violence that has torn the country apart.
In a statement on his official website, President Viktor Yanukovych said his government and the opposition have agreed to "negotiations aimed at cessation of bloodshed and stabilization of the situation in the country for the sake of civil peace."
Opposition leader Vitali Klitschko said in a statement on his website that both sides reached an agreement on the negotiations and that the next round of talks would be held Thursday.
The website quoted Klitschko as saying: "We have received assurances from Yanukovych that there would be no assault on Maidan (the protest camp in Kiev). Literally, it means a truce. Today a key goal is to stop the bloodshed that authorities have provoked and unleashed. Now we will see how Yanukovych will stick to his word after promised sanctions from the West."
The leader of one opposition group, however, vowed to continue to fight. Dmitro Yarosh, leader of Ukraine's far-right Pravy Sector, said on his Facebook page that he rejects the truce called by Yanukovych.
The announcements — the first significant sign of progress since the anti-government protests began nearly three months ago — came just one day after brutal clashes between demonstrators and police left at least 28 people dead and nearly 450 injured, according to the Ukraine Health Ministry.
Word of the possible truce was made public as the State Department began initiating sanctions on the Ukrainian government, a senior U.S. official told NBC News.
Those sanctions restrict visas of "some 20" Ukrainian government officials and others involved in the crackdown. The list of names legally couldn't be released, a senior State Department official said, but it includes "the full chain of command that we consider responsible for ordering the violence last night."
The official said the sanctions can be reversed if the truce holds — or stepped up if it falls apart.
At a news briefing during a summit of North American leaders in Mexico on Wednesday night, President Barack Obama expressed hope.
"If the truce is implemented, it could provide space for the sides to resolve their disagreements peacefully," he said, adding that the U.S. and its European partners would continue to engage with all sides.
Earlier in the day, Obama condemned the violence in Ukraine, saying that the U.S. holds the government "primarily responsible for ensuring they are handling protesters peacefully" and that "there will be consequences if people step over the line."
"We expect the Ukrainian government to show restraint, to not resort to violence," Obama said. "We expect peaceful protesters to remain peaceful."
And before that, Secretary of State John Kerry said U.S. sanctions against Ukraine were possible. The White House first threatened to impose sanctions against the Eastern European nation nearly two months ago.
NATO Secretary General Anders Fogh Rasmussen also weighed in Wednesday night, urging the government to refrain from violence — or risk endangering relations.
"If the military intervenes against the opposition, Ukraine's ties with NATO will be seriously damaged," he said.
Ukraine officials have been engaged with the Western military alliance for potential membership since the country gained independence from the Soviet Union in 1991.
Thousands of demonstrators massed Wednesday in central Kiev against a hellish backdrop of flames and black smoke. Tensions were running high as demonstrators forced their way into the post office on Independence Square, the crucible of the protest movement, after a nearby building they had occupied was burned down amid the previous night's brutal clashes with police.
Ukraine's leading security agency Wednesday had also accused protesters of seizing hundreds of firearms from its offices and called for a nationwide "anti-terrorist" campaign to restore order to the fiercely divided nation.
Meanwhile, President Yanukovych fired the chief of the country's armed forces.
Wednesday's developments came ahead of an emergency meeting Thursday in Brussels, where European Union ministers, like Kerry, said they were considering levying sanctions against Ukraine.
Parts of Kiev have been in a state of near-paralysis since November after Yanukovych ditched a deal with the European Union and struck a loan scheme with Russia to float its ailing economy.
Protests began peacefully last year but have been increasingly characterized by smaller, more extreme elements — many aligned with the far right — who have clashed with riot police.
While the demonstrations started as a rejection of the Russia-leaning government policies, protesters said they now seek to "oust a corrupt and brutal regime," according to a post by the opposition-run "Euromaidan" Facebook group on Wednesday morning.
Tuesday's violence shattered weeks of relative calm in the capital and was sparked by Russia's announcement that it was ready to resume its loan package to the Ukraine. Some in the opposition saw this as an indication that the two countries had struck a deal and that the government was intent on standing firm against the protesters.
Maria Stromova, Jeff Black, Catherine Chomiak and Albina Kovalyova of NBC News contributed to this report.