KYIV, Sep 18 (NEW YORK TIMES) - Russian President Vladimir Putin pledged to stay the course in his campaign against Ukraine, warning if counterattacks continue a “more serious” military response will be unleashed.

Putin remained steadfast despite strong evidence that his forces incurred heavy losses in the Ukraine counteroffensive this month.

The Russian leader said the main goal of the campaign continues to be “the liberation of the entire territory of Donbas” – the areas of eastern Ukraine including Donetsk and Luhansk that are largely Russian speaking.

“The plan is not subject to adjustment,” Putin said. “Our offensive operations in Donbas itself do not stop. They are going at a slow pace … The Russian army is occupying newer and newer territories.”

He accused Ukrainian forces of attempts to carry out “terrorist acts” and causing damage to Russian civilian infrastructure.

“We are really quite restrained in our response to this for the time being,” Putin said at a news conference on Friday. “If the situation continues to develop in this way, the response will be more serious.”