Several European Union foreign ministers have accused Russia of invading eastern Ukraine, saying Moscow should be punished with harsh additional economic sanctions.
Swedish Foreign Minister Carl Bildt said on August 29 that "we have to be aware of what we are facing: We are now in the midst of the second Russian invasion of Ukraine within a year."
He spoke as EU foreign ministers met informally in Milan ahead of a working session on August 30.
Dutch Foreign Minister Frans Timmermans said that "if Russia does not change its stance, then we can't do anything but sharpen ours."
Estonian Foreign Minister Urmas Paet said the EU "should be ready to move forward with possible new measures against Russia" because the situation continues to worsen.
Luxembourg's Foreign Minister Jean Asselborn said all options except military action will be considered to punish Russia for pursuing "the wrong path."
The EU foreign ministers are expected at their talks in Milan to propose fresh sanctions against Russia for consideration at the August 30 summit in Brussels.
Earlier on August 29, French Foreign Minister Laurent Fabius said Paris had evidence of "unacceptable" intervention by Russian troops in eastern Ukraine.
Speaking to the French TV station France 24, Fabius also said that EU sanctions against Russia would probably be reinforced if Moscow does not quickly change its behavior.
Meanwhile, in a new report, the United Nations said the conflict in eastern Ukraine has killed nearly 2,600 people since mid-April
The report noted "serious human rights abuses" that included abductions and torture committed "primarily" by pro-Russian separatists.
Presented in both Geneva and Kyiv on August 29, the report also documented violations committed by Ukrainian forces in their efforts to recapture territory from rebels.
The UN said the sharp increase in casualties -- around 36 people each day -- is explained by fighting in densely populated areas.
It said it is not known precisely how many people remain in captivity in Ukraine, but at least 468 were thought to be held by various armed groups as of August 17.
The UN's high commissioner for human rights, Navi Pillay, said the "deliberate targeting of civilians is a violation of international humanitarian law, and more must be done to protect them."
With reporting by Reuters, AP, Interfax, and dpa