Ukrainian President Volodymyr Zelenskyy has called on the international community to make a concerted effort to support countries that see their sovereignty and territorial integrity threatened by larger powers.

In a virtual speech addressing defense ministers and senior officials from 42 countries attending this year’s Shangri-La Dialogue security conference in Singapore, the Ukrainian leader said the world “must always support diplomatic actions to forestall violence and war.”

Replying to a question about concerns that a crisis similar to Russia’s invasion of Ukraine could erupt in Asia, Zelenskyy stressed the need to support countries that are in need of help, particularly when faced with a larger and better-armed adversary that does not respect the rules-based international order.

“We must not leave them behind, at the mercy of a more powerful country,” he said.

The Ukrainian leader underlined that no one benefits from war apart from certain “ambitious political leaders,” which is why the international community “must break the ability of any given country to block seas and destroy freedom of navigation.”

“If there is a way to solve these issues diplomatically, then we need to do this, but it must be a pre-emptive way, not one that comes after hostilities have broken out and there are numerous casualties,” he added.

At the same time, Zelenskyy called for the full restoration of international law by reforming the United Nations, particularly the U.N. Security Council, where all five permanent members wield veto power over any resolution.

The Ukrainian leader argues that the UNSC, which has failed to adopt draft resolutions to end the Ukraine crisis, does empower many people with a strong voice, especially on issues of vital importance.

“If this reform had taken place before Russia’s war, we would have been able to respond to any aggression, not only Russia’s but also on a global level,” Zelenskyy said, adding that Moscow must be held accountable for the invasion. The Ukrainian leader alleged that Russia has unleashed a campaign of mass destruction, killings and torture, while also employing prohibited munitions and threatening to use chemical and nuclear weapons.

Zelenskyy’s call for UNSC reform echoed a similar push a day earlier by Prime Minister Fumio Kishida in his keynote address at the international security forum.

Kishida, who in his speech referred to strengthening the functions of the U.N. as one the five pillars for his vision of a more secure Indo-Pacific region, said that Russia — a permanent Security Council member — engaged in an “outrageous act” that has shaken the very foundations of the international order, causing the U.N. to face challenging times.

“No time can be lost in reforming the United Nations, which should serve as the guardian of peace,” said Kishida.

Kishida said Japan, which will join the Security Council as a nonpermanent member in 2023 for a record 12th time, will work “tirelessly” to reform the body and seek a way forward for global governance that responds to new challenges facing the international community.