"The European Union supports the current effort to reform the UN. These reforms are badly needed," Tusk said in his address.
He went on saying that leaders of the international community should equip the United Nations with tools to fulfill its agenda collectively. For example, more unity is needed to resolve the ongoing conflicts in Syria and Myanmar and a rapidly worsening crisis in Venezuela.
The EU is ready to step up to help its neighbors to build their security and peacekeeping operations in cooperation with NATO and African countries, Tusk said.
On Tuesday, Secretary-General Antonio Guterres said he is committed to reforming the world body in order to make it more effective and capable of responding to current global challenges.
UN Must Help Uncover Malicious Cyber Actors, Name Responsible Parties
"The anonymity of cyber space is used by external actors to cloak malicious political interference," Tusk said. "The United Nations should help expose this phenomenon, attribute responsibility."
Tusk added that the UN must make efforts to increase democratic resilience as well.
In the recent years, Europe has taken actions against the use of disinformation and propaganda, which have become problems not only for EU countries, Tusk said.
On Tuesday, Tusk said the European Union and NATO will expand cooperation in cybersecurity and countering illegal migration under the framework of a joint declaration.