In this photo released by Russian Foreign Ministry Press Service, Iranian Foreign Minister Mohammad Javad Zarif, right, and Russian Foreign Minister Sergey Lavrov greet each other by touching elbows and wear face masks to curb the spread of COVID-19 prior to their talks in Tehran, Iran, Tuesday, April 13, 2021. Iran's foreign minister warned Tuesday that an attack on its main nuclear enrichment site at Natanz affects ongoing negotiations in Vienna over its tattered atomic deal with world powers. (Russian Foreign Ministry Press Service via AP)