The heads of government of the world's richest democracies are grappling with the challenges posed by China and Russia at a three-day summit.
Moscow has said it is ready to use its nuclear arsenal to defend its "territorial integrity" if necessary.
As Iran continues to get closer to Middle East nations, the clear and present danger of a nuclear Iran is only a threat to Israel.
Ukraine is collaborating with the Nuclear Emergency Support Team (NEST), a unit of atomic experts that's run by the National Nuclear Security Administration, to deploy the radiation sensors.
Dmitry Medvedev: "In place of the American military, I would immediately make a fake trunk with false nuclear codes in case he wins, so as to avoid fatal consequences."
Israel’s window of opportunity to delay the Iranian nuclear program may still be open.
Putin denies having any intention of employing nuclear weapons in Ukraine.