"We need our partners to increase pressure on Russia to stop this terror. Those Russia will listen to are certainly the United States, the other G7 and G20 countries, and Europe," Zelenskyy said. "We must remember that Europe has tools to pressure the aggressor, primarily through its energy sector, shadow oil fleet and financial system."
The president also stressed the need to strengthen Ukraine's air defenses.
"We must take steps to strengthen our protection, first and foremost our air defense. I thank all the leaders who remain active and do not lose a single day," he wrote.
On the evening of July 3, Russian forces launched a large-scale attack on Sumy using guided aerial bombs and drones. A guided bomb strike on one of the city's central streets killed at least four people, including a 5-year-old child. Another 27 people were injured.
The strike damaged an apartment building, and people may still be trapped under the rubble.
Earlier on July 3, Russia also launched a large-scale attack on Zaporizhzhia with guided aerial bombs and drones. The strikes damaged residential buildings and a business, killing at least one person and injuring 21 others.
One more person was injured in a subsequent evening strike on Zaporizhzhia.