The Ukrainian parliament will convene on February 27 to vote on a new pro-Western government.
Pro-European Union opposition leader Arseniy Yatsenyuk has been nominated to be prime minister in a new government.
Yatsenyuk, 39, had been one of the top leaders of the antigovernment protest movement that erupted after ousted President Viktor Yanukovych declined to sign an association agreement with the European Union in November.
In other nominations -- which were announced to demonstrators on Independence Square on February 26 -- career diplomat Anatoliy Deshchytsa was nominated for the post of foreign minister.
Deshchytsa was among Ukrainian diplomats who signed a statement of solidarity with antigovernment protesters earlier this month.
Among the Euromaidan opposition figures offered cabinet positions was Dmytro Bulatov, who was nominated to be minister of sport and youth.
Bulatov was tortured for days and had part of his ear cut off earlier this month.
Meanwhile, U.S. Secretary of State John Kerry warned Russian on February 26 that it would be making a "grave mistake" if it used its military to intervene in Ukraine.
Kerry told reporters in Washington that Russia has repeatedly spoken against foreign military intervention in Libya, Syria, and other places and it "would be important for them to heed those warnings as they think about options" in Ukraine.
Earlier Wednesday, President Vladimir Putin ordered massive Russian military maneuvers in western Russia.
Russian Defense Minister Sergei Shoigu said the maneuvers involve some 150,000 troops, 880 tanks, 90 aircraft, and 80 navy ships.
Moscow also said it was taking measures to defend its Black Sea Naval Fleet, which has a major base in the Ukrainian city of Sevastopol.
NATO Secretary-General Anders Fogh Rasmussen offered alliance support to Ukraine.
"NATO allies will continue to support Ukrainian sovereignty and independence," he said. "We will continue to support Ukraine's territorial integrity and democratic development. And we will continue to uphold the principle of [the] inviolability of frontiers."
And Kerry also said that Washington is considering providing $1 billion in loan guarantees to the new Ukrainian government.
He added that the Obama administration would consider additional aid for Ukraine and was consulting with the European Union and international financial institutions on the aid issue.
White House spokesman Josh Earnest said the United States strongly supports efforts by Ukraine's former opposition to form a unity government, and said Washington urges "outside actors in the region" to respect Ukraine's sovereignty.
In Ukraine’s autonomous Crimean republic on February 26, anti-Russian protesters stormed the regional parliament, disrupting a special session on the Ukrainian crisis.
Russian speakers in Crimea and elsewhere in Ukraine have been alarmed by last week’s political upheaval and a vote by parliament to revoke a law under which Russian was an official language in predominantly Russian-speaking areas in Ukraine’s east and south such as the Crimea.
Protest leader Vitali Klitschko, who says he’ll run to be Ukraine’s new president, offered assurances to Russian-speakers in Crimea that Ukraine’s new authorities won’t trample on their lives and customs.
"Dear residents of Crimea and Sevastopol, do not allow to be used in the schemes and plans of political adventurers," he said. "Do not allow blood to be shed and the country to be torn apart. I, Vitali Klitschko, state with full responsibility that there are no mythical radicals and nationalists, you have been made to be scared of, on their way to you and have no plans to interfere with the life and customs in the peninsula."
Written based on reporting by Reuters, AFP, and RFE/RL correspondent Rikard Jozwiak