Russia has agreed to resume gas supplies to Ukraine over the winter in a deal brokered by the European Union.

The deal will also ensure gas supplies to EU countries via Ukraine are secure.

The agreement follows months of talks between EU officials and the Russian and Ukrainian energy ministers.

The terms include the EU acting as guarantor for Ukraine's gas purchases from Russia and meeting outstanding debts.

"Unprecedented levels of EU aid will be disbursed in a timely manner, and the International Monetary Fund has reassured Ukraine that it can use all financial means at its disposal to pay for gas," the European Commission said in a statement.

"Further work with the international financial institutions on financial assistance to Ukraine, also in relation to gas supplies, will still continue. But all three sides are reassured that Ukraine will have the necessary financial means."