MOSCOW, Dec. 30 - The leaders of Russia, Ukraine, France and Germany have agreed to extend the Minsk peace accord on Ukraine into 2016, the Kremlin said in a statement on Wednesday, following a phone call between the four leaders, Reuters reported.

Extension of the agreement was widely expected as a ceasefire has been broadly holding in eastern Ukraine since September, though sporadic clashes have continued between pro-Russian separatists and Ukrainian government forces and many of the agreement's terms are far from being implemented.

The original terms of the Minsk peace deal, reached in February, were meant to be implemented by the end of 2015, culminating with the restoration of Ukraine's full control over its border with Russia.

The Kremlin statement said that the four leaders had agreed on the need for full observance of a ceasefire, and had also backed more active discussions by the Ukraine Contact Group aimed at rapid adoption of a law about regional elections in rebel-held areas.

Talks between the four leaders take place regularly as their four countries are the co-signatories of the Minsk peace deal.

Poroshenko conferred with Merkel on Tuesday "to coordinate positions", his office said in a statement.

Poroshenko's office also said pro-Russian rebels "increasingly violate the truce and engage in provocations" in an industrial region approximately the size of Wales that is home to about 3.5 million people and the centre of the splintered nation's coal and steel wealth.

German Foreign Minister Walter Steinmeier urged the two fighting sides "to respect the ceasefire in the conflict zones, in the interests of the people".

Last week Ukraine and pro-Russian insurgents reached a "New Year" truce agreement in another effort to stop the violence in the war-scarred ex-Soviet state.

A September 1 truce agreement significantly calmed deadly exchanges of artillery and missile fire along a 30-kilometre-wide (19-mile-wide) buffer zone separating rebel-run territory from the rest of Ukraine.

But a new upsurge in violence that began two weeks ago threatened the September deal.

"The Minsk process will continue in 2016 and will hopefully be better than this year," Oleksandr Turchynov, the head of Ukraine's Security and Defense Council, said Tuesday.

The United Nations estimates that more than 9,000 people -- most of them civilians -- have died since the rebel revolt began in April 2014. (rt/afp/ez)