A nuclear arms control treaty between the United States and Russia is set to expire on Friday. The two nuclear powers plan to develop banned missiles, raising concerns about a new arms race.
The Intermediate-Range Nuclear Forces Treaty, or INF, was signed by the US and the former Soviet Union in 1987 during the Cold War.
The treaty prohibits the production, possession and test-firing of ground-based ballistic and cruise missiles with a range of 500 to 5,500 kilometers. The two countries have scrapped more than 2,600 nuclear missiles.
In February, Washington notified Moscow that it would withdraw from the INF because of Russia's alleged violations. Russia responded that it would also exit the treaty.
The pact is to become null and void on Friday under the provision that it will expire six months after the US notice.
UN Secretary-General Antonio Guterres said on Thursday that the world will lose an invaluable brake on nuclear war when the treaty expires. He said the expiration of the treaty will likely heighten, not reduce, the threat posed by ballistic missiles.
The US plans to develop ground-based intermediate-range missiles. Russia plans to convert its sea-launched cruise missiles to land-based versions.
The two countries are calling for a new nuclear disarmament framework involving China. The US is especially cautious about China's rapid build-up of intermediate-range missiles. But Beijing has declined negotiations for such a framework.
Military analysts have expressed concern about a new arms race between the three powers following the expiration of the treaty that had restricted US and Russian nuclear weapons for about three decades.