Russian President Vladimir Putin on Sunday again called for political compromise in Ukraine, saying a peace deal should ensure the rights of all Russian-speaking people in Ukraine's east.
Putin's comments came as Russian news outlets reported new fighting in Ukraine near the Russian border, including an apparent bomb blast targeting the Donetsk railway line. Russian media also cited an attack by pro-Russian separatists on a Ukrainian armored column outside the city of Luhansk. There were no immediate casualty reports.
On Friday, Ukrainian President Petro Poroshenko declared a week-long unilateral cease-fire in the region, and said he would negotiate with separatists who are not implicated in "murder and torture" in eastern Ukraine.
Putin on Sunday said the truce "should result in dialogue between all conflicting sides." He called such talks "the keystone of success."
French President Francois Hollande and German Chancellor Angela Merkel also urged the Russian leader to boost border security to stop the flow of military hardware and fighters into eastern Ukraine.
Poroshenko's cease-fire declaration - rejected by separatist leaders - ordered Ukrainian forces to halt all operations for seven days. But he said the order did not mean Ukrainian troops would not fight back if attacked.
Ukraine and Russia have been locked in a tense standoff since late February, when Ukrainian protesters forced their Russian-backed president to flee the country after months of anti-government demonstrations in Kyiv.
Weeks later, Russia retaliated by annexing Ukraine's Crimean peninsula, following a secession vote which both Kyiv and the West condemned as staged. Armed pro-Moscow separatists launched their rebellion in the east of the country in April.