UNITED NATIONS, Dec. 31 (Xinhua) -- In his message on the New Year, United Nations Secretary-General Antonio Guterres is calling for unity among the global community to tackle overwhelming challenges and defend values shared by all.

"On New Year's Day 2018, I am not issuing an appeal. I am issuing an alert, a red alert for our world," said the secretary-general on Sunday, which is the last day of 2017 in some countries but New Year's Day in others.

"As we begin 2018, I call for unity. We can settle conflicts, overcome hatred and defend shared values. But we can only do that together," he said.

Recalling that last year he urged that the year of 2017 be a year for peace, the UN chief noted that unfortunately, in fundamental ways, the world went in reverse.

Perils, including deepening conflicts and new dangers emerged, and global concerns over nuclear weapons reached the highest since the Cold War, he added.

At the same time, impacts of climate change worsened at an alarming rate, inequalities grew and there were horrific violations of human rights.

"Nationalism and xenophobia are on the rise," said Guterres.

Underscoring his belief that the world can be made more safe and secure, conflicts can be settled, hatred can be overcome and shared values defended, he emphasized that unity is indispensable to achieving these goals.

"Unity is the path. Our future depends on it," said the secretary-general, urging leaders everywhere to resolve in the New Year to: "Narrow the gaps. Bridge the divides. Rebuild trust by bringing people together around common goals."