Nur-Sultan, Aug 30 (IANS): Kazakh President Kassym-Jomart Tokayev said that closure the former Semipalatinsk nuclear test site has largely reduced the threat of nuclear proliferation to the international community.

Semipalatinsk was the primary testing venue for the Soviet Union's nuclear weapons, with over 450 tests carried out since 1949, reports Xinhua news agency.

On August 29, 1991, then President Nursultan Nazarbayev signed an executive order to shut down the site.

Tokayev said the Semipalatinsk site near Semey city had caused intensive radioactive contamination of the surrounding areas of 300,000 square km, with more than 500,000 people exposed to direct radiation.

After the closure of the test site, the Kazakh government prioritized social rehabilitation and long-term safety of the area, said Tokayev, adding that a comprehensive environmental survey covering 18,500 square km will be completed next year.

In 2009, the UN General Assembly declared August 29 as the International day of action against nuclear testing.