China said on Monday that it has always adhered to a nuclear strategy of self-defense and does not participate in any arms race, in response to a report claiming that China is increasing its stockpile by about 100 warheads per year — faster than any other country.

The Stockholm International Peace Research Institute released its annual report on global nuclear forces on Monday, saying that China currently possesses 600 nuclear warheads, ranking third in the world.

Foreign Ministry spokesman Guo Jiakun said at a daily news briefing that China will not comment on the report.

He emphasized that China has always maintained its nuclear forces at the minimum level required for national security and will remain firmly committed to safeguarding its legitimate security interests and to maintaining world peace and stability.

China upholds the policy of no first use of nuclear weapons at any time and under any circumstances, and it has made an unconditional commitment not to use or threaten to use nuclear weapons against non-nuclear-weapon states and nuclear-weapon-free zones, he said, adding that China is the only nuclear-weapon state to adopt such a policy.