United Nations, United States --UN Secretary-General Antonio Guterres warned Tuesday that only a "global vaccination plan" could end the Covid-19 pandemic and called the uneven roll-out of vaccines around the world "immoral."

Speaking as fears of the new Omicron strain of the virus rattled world markets, Guterres reiterated his longstanding calls for a coordinated pandemic response at a virtual meeting of foreign ministers from the Group of 77 coalition of developing countries and China.

"The only way out of a global pandemic -- and out of this unjust and immoral situation -- is through a global vaccination plan," he said.

"Despite the development of effective vaccines in record time, more people have died in 2021 than in 2020," he added, saying the disease "continues to wreak havoc on developed and developing countries alike."

"Everyone, everywhere must have access to Covid-19 vaccines, tests and treatment," he said.

Guterres said "the entire United Nations system" backed the strategy laid out by the World Health Organization to vaccinate "40 percent of people in all countries by the end of this year, and 70 percent by the middle of 2022."

According to UN figures, only 12 middle-income countries, 27 higher-income countries and 71 very high-income countries have reached that 40 percent mark among their populations.

No country classified as low income has reached that same level. As of November 25, 4.15 billion people have received at least one dose of Covid vaccine, with 3.2 billion of them fully vaccinated.