Speaking on ABC News’ Good Morning America, Zelenskyy said that it was vital for Ukraine and its backers to stand firm against Russia.

“The plan of victory is strengthening of Ukraine; that's why we're asking our friends, our allies, to strengthen us. It's very important,” he said.

Zelenskyy added: “I think that we are closer to peace than we think. We are closer to the end of the war. We just have to be very strong, very strong.”

The Ukrainian president is in America for a visit that will culminate in a meeting with President Biden during which he will present his Victory Plan, which sets Ukraine’s strategy for ending the war.

Zelenskyy is expected to again appeal to the U.S. for permission to strike military targets deep inside Russia using Western weapons, a move that Vladimir Putin says would constitute a serious escalation and be viewed as a direct provocation by NATO.

Zelenskyy’s American visit comes at a key time in the war; while heavy fighting continues in eastern Ukraine, Kyiv says hundreds of square miles of territory inside Russia’s Kursk region remain under its control following its bold offensive in August.

Referencing the surprise attack, Zelenskyy told viewers that the Kursk operation had exposed Putin’s vulnerabilities.

“He’s afraid very much,” said Zelenskyy. “Why? Because his people saw that he can't defend—that he can't defend all his territory.”

Zelenskyy is due to travel to Washington later this week, where he will meet President Biden as well as the two candidates up for election, Kamala Harris and Donald Trump.