Drawing blood at an H.I.V. clinic in South Africa last year. The research networks’ large footprint has enabled them to develop tools to prevent and treat H.I.V., including in marginalized or rare populations.

United Nations Secretary General António Guterres addressing the general assembly on Tuesday.

Wildfires burning in southwestern France this summer.

A vendor cooled off with a frozen water bottle in a market in Seoul on Aug. 6.

Havana in 2019. The C.I.A.’s action coincides with stepped-up efforts by U.S. intelligence agencies to get a better understanding of the situation on the ground inside Cuba.

Land charred by the Cairngorm wildfire in Aviemore, Scotland, on Tuesday.

In red, Mehmet Fatih Cicekli, governor and cyclist, in April. Now he is just a cyclist.

A health clinic in Johannesburg that was closed in 2025, following cuts in U.S. aid.

A health worker in the town of Mongbwalu, Democratic Republic of Congo, collecting medication for patients suspected of having Bundibugyo virus last month.

A health worker takes the temperature of a motorcyclist passing through a checkpoint to enter the city of Goma, Democratic Republic of Congo, as part of the response to Ebola.

Health workers disinfected a coffin containing the body of a man presumed have died of Ebola in the Democratic Republic of Congo.

Clifford E. Stanley, a retired mortgage broker, traveled to Nuuk, Greenland, to make residents an offer.

Pope Leo XIV speaks during the presentation of “Magnifica Humanitas,” his first encyclical, at the Vatican on Monday.

Pope Leo has made artificial intelligence a central theme of his first year as pontiff.

Pope Leo XIV at the presentation of his first encyclical letter, “Magnifica Humanitas,” at the Vatican on Monday. In it, he outlined his desire to protect human dignity and agency in an age of artificial intelligence.

Ernesto Soberón Guzmán, Cuba’s ambassador to the U.N., in New York on Wednesday.

Solar panels and wind turbines in north-central China. Renewable is becoming more affordable in many countries.

Raúl Castro is the former president of Cuba and younger brother of Fidel Castro.

President Richard M. Nixon visiting Beijing in 1972.

A scorching day in Seville, Spain, last July.