"The release of hostages after many months of war between Israel and Hamas is a deeply meaningful moment," Zelensky wrote.
This follows Zelensky saying on Saturday that Ukraine had captured two North Korean soldiers in Russia's Kursk region.
Kyiv says that North Korean troops are fighting in the Kursk region, where Ukraine launched an incursion in August.
"We are preparing to resume diplomatic relations with Syria and cooperation in international organizations," Zelensky said.
Leshchenko, in an interview with the 'Post' on Monday, expressed fear that Russian attacks on Ukraine will increase and intensify over the next few days and weeks.
The Ukrainian president lit a hanukkiah with several Ukrainian rabbis following a massive Russian airstrike on Ukraine.
Ukrainian President Volodymyr Zelensky said that a freeze on the war would only allow Putin to rearm.
Ukraine says it accepts that it cannot join the alliance until the war is over but extending an invitation now would show Russia's Putin that he could not prevent Kyiv from becoming a NATO member.
The launch was the latest sign of rapidly mounting tensions in the 33-month-old war after Ukraine fired US and British missiles at targets inside Russia.
Zelensky said he also spoke with European and US officials to help him get Israel to lend Ukraine support, especially with air defenses.