BRUSSELS -- The European Union has formally prolonged economic sanctions against Russia for six months over Moscow's aggressive actions in Ukraine.

The European Council said in a December 21 statement that it formalized a decision made by EU leaders last week to extend the existing restrictions against Moscow until July 2018.

The EU measures, which mainly target the Russian banking and energy sectors, were first imposed in the summer of 2014 and have been extended every six months since then.

The December 14 agreement in Brussels followed a debate among EU leaders in which French President Emmanuel Macron and German Chancellor Angela Merkel pushed for an extension.

Sources who were not authorized to speak on the record told RFE/RL that some countries including Hungary, Italy, and Slovakia voiced reservations about the sanctions but agreed that EU unity on the matter was more important.

Speaking after the December 14 summit in Brussels, European Council President Donald Tusk said that all member states were "totally united when it comes the role of sanctions against Russia."

"It was the first time that we decided on this without any disputes and arguments," Tusk added.

Merkel said the leaders had "a very intense discussion on the question of prolonging sanctions" and all agreed that more progress was needed carrying out the peace process outlined in the Minsk agreements.

The EU and the United States imposed sanctions in response to Russia's seizure of Ukraine's Crimea region in March 2014 and its support for separatists in a conflict that has killed more than 10,300 people in eastern Ukraine since April 2014.

Several cease-fire deals announced as part of the Minsk accords -- September 2014 and February 2015 pacts aimed to resolve the conflict -- have failed to hold.