NATO Secretary General Jens Stoltenberg (C) addresses a joint meeting of the U.S. Congress in Washington D.C., the United States, on April 3, 2019. Jens Stoltenberg said on Wednesday that the military alliance does not want a "new arms race" with Russia while urging Moscow to keep compliance with a landmark arms control treaty. (Photo: Xinhua)

Nuclear powers continue to modernize their arsenals, researchers said Monday, warning that tensions were rising and the outlook for arms control was "bleak."

"The loss of key channels of communication between Russia and the USA... could potentially lead to a new nuclear arms race," said Shannon Kile, director of the nuclear arms control program at the Stockholm International Peace Research Institute (SIPRI) and co-author of the report.

Russia and the US account for more than 90 percent of the world's nuclear weapons.

Kile was referring to the future of the New START treaty between the US and Russia, which is set to expire in February 2021.

It is the final nuclear deal still in force between the two superpowers, aimed at maintaining their nuclear arsenals below Cold War levels.

"Discussions to extend New START or to negotiate a new treaty made no progress in 2019," Kile noted.

The number of nuclear warheads declined in 2019.

At the start of 2020, the US, Russia, Britain, China, India, Pakistan, Israel and North Korea together had 13,400 nuclear arms, according to SIPRI's estimates, 465 fewer than at the start of 2019.

The decline was attributed mainly to the US and Russia.

While the future of the New START treaty remains uncertain, Washington and Moscow have continued to respect their obligations under the accord.

But both nations "have extensive and expensive programs under way to replace and modernize their nuclear warheads, missile and aircraft delivery systems, and nuclear weapon production facilities," it added.

AFP