Pro-Russian rebels
Members of the armed forces of the separatist self-proclaimed Donetsk People's Republic drive a tank Reuters

Latvia's foreign minister has warned that fresh violence in eastern Ukraine was threatening a ceasefire deal and could prompt the European Union to impose fresh penalties on Moscow.

Russia and Ukraine signed a truce in the Belarussian capital of Minsk in September, but violence has erupted in Ukraine in recent weeks.

Latvia's foreign minister, who has a prominent role in EU diplomacy, said the bloc would consider ways to pressure Moscow to stick to the ceasefire if the violence continued.

"If Russia... does not implement or does not agree to implement those agreements, and definitely we are facing the very serious situation, in that case I believe we will also have to look at EU level at what kind of additional pressure we can also have," Rinkevics told journalists in the Latvian capital Riga.

"The Minsk agreements are the only agreements that Russia also has signed. But the situation is getting serious. I don't want to declare Minsk agreements dead yet," he said.

Latvia, which was previously part of the Soviet Union, has been one of Russia's strongest critics as the crisis in eastern Ukraine escalated in 2014.

More than 4,800 people have been killed as a result of the fighting in eastern Ukraine since April, according to United Nations figures.

Kiev, along with allies the United States and the European Union, has accused Russia of fuelling the conflict in its east where pro-Russian separatists have fought with government troops since April.

"But if there is a serious deterioration then I think the EU has to... think what we can do on our part to facilitate implantation of the agreement; dialogue, but also what kind of additional pressure there can be," Rinkevics said.