President Volodymyr Zelenskiy demanded a special United Nations tribunal impose "just punishment" on Russia for its invasion of Ukraine, including financial penalties and stripping Moscow of its veto power in the Security Council.
Hours earlier, president Vladimir Putin had ordered Russia's first wartime mobilisation since World War Two.
* Russia and Ukraine carried out an unexpected prisoner swap, the largest since the war began and involving almost 300 people, including 10 foreigners.
* Putin's thinly veiled threat to use nuclear weapons was "dangerous and reckless rhetoric", NATO's secretary general Jens Stoltenberg said.
* "If the territorial integrity of our country is threatened, we will without doubt use all available means to protect Russia and our people - this is not a bluff," Putin said.
* Security forces detained more than 1,300 people in Russia at protests denouncing mobilisation, a rights group said.
* U.S. President Joe Biden accused Russia of violating the tenets of membership in the United Nations by invading Ukraine and said Moscow was making "irresponsible" threats to use nuclear weapons.
* Canadian Prime Minister Justin Trudeau condemned Putin's military mobilization order. Trudeau and other Western allies said threats to use nuclear weapons show Russia's Ukraine campaign was failing.
* European Union foreign ministers agreed to prepare new sanctions on Russia and increase weapons' deliveries to Kyiv.
* Foreign ministers from the G7 economies confirmed in a meeting in New York their cooperation in extending support for Ukraine and responding to food and energy security, the Japanese Foreign Ministry said.
* One-way flights out of Russia were rocketing in price and selling out fast after the mobilisation order.
* In Moscow's first update on casualty numbers in almost six months, Russia's Defence Minister Sergei Shoigu said 5,937 Russian soldiers had been killed since the start of the conflict.
* Pro-Russian figures announced referendums for Sept. 23-27 in Luhansk, Donetsk, Kherson and Zaporizhzhia provinces, representing around 15% of Ukrainian territory.
* Germany nationalised gas importer Uniper and Britain capped wholesale electricity and gas costs for businesses.
* "Those who try to blackmail us with nuclear weapons should know that the weathervane can turn and point towards them," Putin said in his televised address.