Russia's Energy Minister Alexander Novak addresses a news conference after a meeting of the Organization of the Petroleum Exporting Countries (OPEC) in Vienna, Austria, December 10, 2016. REUTERS/Heinz-Peter Bader

MOSCOW (Reuters) - Global oil markets will reach a supply-demand balance in late 2017 or early 2018 if a pact to cut output is extended, Russia’s energy minister was quoted by local news agencies as saying.

“Judging from the current dynamics in the decline of the oil and oil products inventories, the markets will see such decline in inventories by the end of 2017 - early 2018, which will lead to cuts in inventories to a five-year average,” Alexander Novak was quoted as saying.

The Organization of the Petroleum Exporting Countries and other producers including Russia pledged to cut output by 1.8 million barrels per day (bpd) in the first half of the year to lift oil prices.

But global inventories remain high, pulling crude back below $50 per barrel earlier this month and putting pressure on OPEC to extend the cuts to the rest of the year.

Novak told the agencies that OPEC countries and other leading oil producers would discuss extending the deal in the second half of the year or “maybe further than that”.

He also said that he expected the parameters of the deal to be unchanged, meaning deeper cuts were unlikely.

OPEC and industry sources said there had been discussions about extending curbs until the end of the first quarter 2018, when crude demand is seasonally at its weakest.

Novak added that Russia would keep output cuts of 300,000 barrels per day from the level of October 2016 as stipulated by the December 2016 deal, he added.

He said that Russia’s oil output forecast of 549-551 million tonnes for this year remained the same but could change depending on the outcome of oil producer nation talks in Vienna later this month.