UN Secretary-General Antonio Guterres on Friday expressed his "deep regret" at the ending of the Intermediate-Range Nuclear Forces (INF) Treaty between the United States and Russia.
Stephane Dujarric, his spokesman, said in a statement that Guterres has consistently called on the two parties to resolve their differences through the consultation mechanisms provided for in the treaty and regrets they have been unable to do so.
He notes that, in the current deteriorating international security environment, previously-agreed arms control and disarmament agreements are increasingly under threat, the statement said.
The secretary-general emphasizes the need to avoid destabilizing developments and to urgently seek agreement on a new common path for international arms control, it said.
He calls on Russia and the United States to extend New START, a treaty imposing limits on the number of US and Russian long-range nuclear warheads and launchers, and to undertake negotiations on further arms control measures, it added.
In early July, Russian President Vladimir Putin signed a bill into law, suspending the country's participation in the INF Treaty.
The decision was made in response to the United States' withdrawal from the key arms-control pact, which was signed by the Soviet Union and the United States in 1987.
The United States' withdrawal becomes effective Friday, six months after Washington announced its intention to suspend its treaty obligations.
The INF Treaty required the United States and Russia to eliminate and permanently forswear all of their nuclear and conventional ground-launched ballistic and cruise missiles with ranges of 500 to 5,500 km.
Moscow and Washington had accused each other of violating the agreement in recent years amid increasing tensions.