KIEV, July 10 - Ukraine on Monday asked NATO to start talks over potential membership, an important milestone as the country is battling the Russia-led insurgency and occupation in eastern regions.

President Petro Poroshenko told NATO Secretary General Jens Stoltenberg that Ukraine will seek to begin discussions about a roadmap to join the U.S.-led military alliance.

No timeframe for the talks has been provided, but Poroshenko said Ukraine plans by 2020 to meet NATO standards in major criteria.

Poroshenko, speaking at a press conference alongside Stoltenberg, said he had "clearly stated that we would begin discussion about a membership action plan and our proposals for such a discussion were accepted with pleasure."

Ukraine already been seeking to join the alliance since 2008, but those moves had been derailed by then-President Vitkor Yanukovych, whose pro-Russian policies and corruption had triggered a massive unrest, forcing him to flee to Russia in February 2014.

Moscow moved in March 2014 to annex the Crimean peninsula and later that year started supplies of heavy weapons and personnel to stoke pro-Russian rebellion in Donetsk and Luhansk.

Stoltenberg called on Russia to withdraw its troops from Ukraine and said that the alliance would be supplying hardware to protect Ukraine's computers from cyberattacks.

"Russia must withdraw its thousands of soldiers from Ukraine and stop supporting the militants," Stoltenberg said.

Kiev has accused Moscow of being behind a massive computer virus attack last month that quickly spilled across Ukraine's borders and infected computers worldwide.

At least 69 percent of Ukrainians surveyed in a June poll said they supported joining NATO — a sharp increase from before Moscow's forced annexation of the Crimean Peninsula.

Poroshenko has pledged Ukraine will undertake a series of reforms aimed at qualifying the country for NATO membership by 2020. Those reforms would cover the areas of defense, anti-corruption, governance and law enforcement.

The meeting with NATO's top official comes after Washington appointed Kurt Volker, a former U.S. representative to NATO, as a special representative to Ukraine. (nr/ez)