And in the hours after the accord, brokered in part by Secretary of State John Kerry and Foreign Minister Sergey V. Lavrov of Russia, militants occupying the government building in the name of the newly declared and wholly unrecognized People’s Republic of Donetsk said that they would not be bound by anything Russia had agreed to.

Roman Velikodny, who called himself commandant of the occupied building, said he had no intention of asking militants to leave until after a referendum that would allow residents of the region to choose autonomy from Kiev. “Before they let people openly express their opinions on the future of this land, we won’t leave the building,” he said. “There will be no handing over of weapons and buildings before people express their views.”

Vasili Domashev, who described himself as an aide to the commandant, said the armed men would not leave because they did not trust the Kiev government. “Lavrov and Kerry decided, but who are they to us?” he said as a guard sat beside him, tapping the flat side of a samurai sword against his boot. “We are the Donetsk Republic. We have people who make their own decisions.”

The Geneva agreement — hammered out during six hours of talks between Mr. Kerry; Mr. Lavrov; Andrii Deshchytsia, the interim Ukrainian foreign minister; and Catherine Ashton, the foreign policy chief for the European Union — called on all sides in Ukraine to refrain from violence or provocative behavior and rejected all forms of intolerance, including anti-Semitism.

“All illegal armed groups must be disarmed,” the joint statement said. “All illegally seized buildings must be returned to legitimate owners; all illegally occupied streets, squares and other public places in Ukrainian cities and towns must be vacated.”

In exchange, the interim Ukrainian government agreed to grant amnesty to protesters who leave the government buildings they have occupied and give up their arms, unless they are suspected of murder or other capital crimes. The Kiev government would also ensure that constitutional revisions involve “outreach to all of Ukraine’s regions and political constituencies,” a reference to Russian speakers in the eastern part of the country.