Ukraine's acting President Oleksandr Turchynov has assumed the duties of commander in chief of the country's armed forces. The move was announced in a decree published on the presidential website on February 26.
It came shortly after Ukraine's acting interior minister, Arsen Avakov, announced he has disbanded the country's Berkut special police force.
The 5,000-strong special police have been blamed for violent attacks against demonstrators during the three months of antigovernment protests, which resulted in the deaths of dozens of protesters.
The announcements come as Ukraine's new leaders are seeking a government of national unity after parliament ousted President Viktor Yanukovych on February 22.
A lineup of the new government is due to be presented later on February 26 on Kyiv's Independence Square, the focus of the antigovernmnent protests.
Parliament is expected to vote on the new government on February 27.
Western officials have said much-needed financial aid for Ukraine's battered economy could be discussed once a new government is formed.
Meanwhile, the new authorities are also grappling with separatist calls in eastern Ukraine, Yanukovych's former stronghold, particularly in Crimea, with its largely ethnic Russian population.
There have been pro-Russian protests in Crimea, and the Russian flag has been raised on government buildings in the regional capital, Simferopol, as well as in the port city of Sevastopol, the home of Russia's Black Sea Fleet.
In Simferopol, opposing groups of protesters rallied outside the Crimean parliament on February 26. Hundreds of pro-Russian activists protested against Ukraine's new government. Meanwhile, hundreds of Crimean Tatars who support the new leadership in Kyiv and who oppose calls for Crimea's separation from Ukraine held a rival rally.
Pro-Russian activists also rallied in the eastern city of Kharkiv on February 26, where they raised the Russian flag on city hall.
Russia has accused Ukraine's authorities of "infringing" on the rights of ethnic Russians, and Foreign Minister Sergei Lavrov called on the Organization for Security and Cooperation in Europe (OSCE) to "decisively condemn" the rise of "nationalist and neo-fascist" sentiment in western Ukraine.
Lavrov, who met with OSCE Secretary-General Lamberto Zannier in Moscow on February 25, said the organization should also condemn moves to ban the Russian language and to turn the "Russian-speaking population into "noncitizens."
U.S. Secretary of State John Kerry said the same day that Ukraine should not be forced to make a choice between Russia and the West.
"This is not a zero-sum game," he said. "It is not a West versus East [situation]. It should not be. It is not Russia or the United States or other choices. This is about the people of Ukraine and Ukrainians making their choice about their future."
Kerry was speaking after meeting with Britain's Foreign Secretary William Hague in Washington.
Hague is due to visit Ukraine soon, while Deputy U.S. Secretary of State William Burns arrived in Kyiv on February 25.
With reporting by Reuters, Pravda.con.ua, UNIAN, and Interfax