India and China have added to their nuclear warhead stockpile in the last year while all other nuclear-armed nations like the U.S., Russia and France, continued to modernize their arsenal, according to a recent report from the Stockholm International Peace Research Institute.

India increased its arsenal from an estimated 130-140 nuclear warheads in 2019 to 150 in 2020, whereas China increased its stockpile from an estimated 290 warheads to 320 during the same time, the SIPRI report said on Monday. China and Pakistan, which has an estimated stockpile of 160 nuclear warheads, individually have more nuclear warheads than India, the report added.

China is modernizing its nuclear arsenal and "developing a so-called nuclear triad for the first time, made up of new land and sea-based missiles and nuclear capable-aircraft,” the report said. On the other hand, India and Pakistan were both increasing the size and diversity of their nuclear weapons, it noted.

The SIPRI report on India and China increasing their nuclear stockpile comes at time when the two neighbors are engaged in a six-week-long border stand-off at multiple places along their 3,488 kilometer (2,167 mile) long unmarked border. Although, meetings between senior military personnel and at the diplomatic level have eased tensions, the confrontation continues.

Globally nine states together possessed an estimated 13,400 nuclear weapons at the start of 2020 which is slightly lower than the 2019 count of 13,865, SIPRI Yearbook 2020 said. The drop was largely due to the dismantling of retired weapons by Russia and the U.S., who account for over 90 percent of the world’s stockpile.

Of the 13,400 active nuclear warheads, the SIPRI estimates about 3,720 of the nuclear weapons are deployed with operational forces and another 1,800 are stored in a state of readiness.