The United Nations Security Council on Friday demanded that all parties to armed conflicts engage immediately in a "durable, extensive, and sustained humanitarian pause" to allow for Covid-19 vaccinations.
The 15-member council unanimously adopted and co-sponsored a resolution drafted by Britain last week.
It was seen as a key test of UN cooperation between China and new US President Joe Biden's administration.
The council last year took several months to agree a resolution calling for a pandemic ceasefire due to bickering between Beijing and ex-President Donald Trump's administration.
Britain's UN Ambassador Barbara Woodward said the resolution would help bring vaccines to 160 million people in conflict-affected areas or displaced by conflict, though she added: "Obviously, each of these situations will require further negotiations at country, and even at field and local level."
In the resolution, the council expresses its intention to review specific situations raised by UN Secretary-General Antonio Guterres where Covid-19 vaccination is being impeded and to "consider what further measures may be necessary to ensure such impediments are removed and hostilities paused".
It also asks developed countries to donate vaccine doses to low and middle-income countries and other nations in need, particularly through the international Covax vaccine sharing facility.