Russia expels four British diplomats in the ongoing row over the extradition of Andrei Lugovoi for the suspected murder of Russian spy Alexander Litvinenko.
- Russia says that it will launch a criminal case against Andrei Lugovoi if the United Kingdom provides it with convincing evidence of Lugovoi's involvement in the murder of Alexander Litvinenko.
- Russia and China veto a draft United Nations Security Council resolution sponsored by France, the United Kingdom and the United States calling for sanctions against the Syrian government and President Bashar al-Assad over allegations that the government used chemical weapons in the conflict.
- British cosmologist Stephen Hawking and Russian venture capitalist and physicist Yuri Milner announce " Breaktrough Starshot," a $100 million effort to plan a trip to the sun's closest stellar neighbor, Alpha Centauri, via developing nanotechnology that would put the craft within the star system roughly 20 years after leaving Earth.
- Iran is invited to attend the next round of talks over Syria's future, along with the representatives from the United States, Russia, Saudi Arabia, Turkey, Britain, France, Germany, Jordan, the United Arab Emirates, and the United Nations mediator for Syria, Staffan de Mistura. The next round of the "Vienna II" meeting is expected to start tomorrow and continue Friday in Vienna, Austria.
- Iran, the United States, the United Kingdom, France, Russia, People's Republic of China, Germany, and the European Union (the P5+1) reach a breakthrough agreement on the general framework for an agreement on Iran's nuclear program, but sign no verbal agreement or official document. The deadline for a full deal is June 30, 2015.