Volodymyr Zelensky has vowed to liberate the eastern city of Bakhmut and two other cities in a secret plan.
“We will de-occupy Bakhmut,” the Ukrainian president told reporters in Washington.
“I think that we will de-occupy two more cities,” he added. “I will not tell you what cities, sorry.”
Mr Zelensky said his armed forces had a “very, very comprehensive plan” to complete the goal.
His pledge comes after Kyiv announced the liberation of two villages, Klischchiivka and Andriivka, on the southern tip of Bakhmut over the past week.
It is likely that Ukraine’s armed forces are attempting a double envelopment of Russian troops in the Donetsk region city, which was captured by Moscow last May after some of the most fierce fighting of the war.
Bakhmut is one of three main directions of advance by Ukrainian forces as part of their long-heralded summer counter-offensive.
Anonymous American officials had criticised the tactic, arguing Kyiv’s military planners had diverted too many resources away from the main line of advance towards the Sea of Azov in order to sever Vladimir Putin’s land bridge between mainland Russia and occupied Crimea.
But Ukrainian officials have argued that Bakhmut holds political symbolism after the initial battle for the city became the bloodiest since Moscow launched its invasion in February last year.
While Mr Zelensky refused to reveal the two other cities his forces plan to liberate, Ukraine’s armed forces have announced successes in the direction of the coastal towns of Melitopol and Berdyansk.
He insisted Ukraine would not stop its counter-offensive this winter and hoped to take advantage of Russian weaknesses.
“I’m not the best person for military in the world,” he said, adding that Putin needed to “pause because he really lost people, professional army, lost. They’re dead”.
“We can’t stop this winter,” Mr Zelensky added. “It’s difficult. But we have experience of previous year.”