Harmony with Nature – living a better quality of life while minimizing the use of toxic materials and preserving natural resources – was the focus of the International Mother Earth Day celebration Monday at the United Nations.

United Nations Secretary-General António Guterres has called for a prompt, effective and transparent investigation into recent airstrikes on civilians in Yemen, which claimed at least 50 lives, including children, and injured many others.

The United Nations disarmament chief said on Monday that the world today faces similar challenges to the context that gave birth to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), and that the threat of use of nuclear weapons is growing.

The unity within the Security Council played an essential role in creating the positive momentum that led to a decision by the Democratic People’s Republic of Korea (DPRK) to suspend nuclear tests and launches of intercontinental ballistic missiles, the United Nations chief said Monday, noting however that the 15-member body has so far failed to achieve such unity to tackle the Syrian crisis.