KYIV, UKRAINE -- v>

Ukrainian President Volodymyr Zelenskyy said Saturday that counteroffensive and defensive actions are underway against Russian forces, asserting that his top commanders are in a "positive" mindset as their troops engaged in intense fighting along the front line.

The Ukrainian leader, at a Kyiv news conference alongside Canadian Prime Minister Justin Trudeau, responded to a question about Russian President Vladimir Putin's comment a day earlier that Ukraine's counteroffensive had started -- and Ukrainian forces were taking "significant losses."