The European Union is set to agree a six-month extension of its economic sanctions on Russia on Friday, December 18, once Italy's Prime Minister has discussed the issue with his fellow leaders at a summit in Brussels, diplomats said on Tuesday, according to Reuters.

Italy's Matteo Renzi has been seeking to raise the issue of the sanctions, imposed on Moscow last year over the Ukraine conflict, since last week, when Rome unexpectedly held up approval by EU envoys after an agreement by leaders in November.

European Council President Donald Tusk, who will chair the two-day summit in Brussels from Thursday, said in his invitation letter that he had asked EU envoys to rubber-stamp the sanctions decision on Friday.

Italy's unexpected call for further discussion had caused some EU countries to worry that talks would expose divisions over its policy, which was intended to punish Russia for its support for separatists in eastern Ukraine.

However, Italy, one Europe's biggest importers of Russian gas, says it has no problem with extending the sanctions, but cannot agree to rolling them over without discussion.

Maintaining unity is crucial for diplomatic efforts to push Russia to uphold the Minsk peace agreement and end the Ukraine conflict, which has killed more than 9,000 people since April 2014, according to the United Nations.

In Brussels, diplomats said the EU ambassador's meeting is scheduled for 1400 GMT(0900 ET) on Friday, and the extension can be approved then, once the summit is over. "Once Renzi has raised the issue with leaders at the summit, the sanctions can be prolonged as a procedural matter," an EU diplomat said.

It was not immediately clear when Renzi would speak during the summit, but Thursday's summit dinner, where only leaders and not aides are present, may be his choice, diplomats said.