Ukraine will not surrender to Russia's invasion of the country, Foreign Minister Dmytro Kuleba said Sunday, as he accused Russian President Vladimir Putin of seeking to increase "pressure" by ordering his nuclear forces on high alert.

"We will not surrender, we will not capitulate, we will not give up a single inch of our territory," Kuleba said at a news conference broadcast online.

Kuleba also said Russia dropped its preconditions for talks after suffering military setbacks, adding that Ukraine would attend the talks to listen to what Russia had to say.

Ukrainian President Volodymyr Zelenskyy on Sunday said Russia had agreed to talks at a venue on the Belarusian border, the first since Russia unleashed a full-scale invasion of its neighbor last week.