Joe Biden has approved a new US nuclear strategy to prepare for possible coordinated nuclear confrontations with Russia, China and North Korea, according to a New York Times report published on Tuesday.

The deterrent policy takes into account a rapid build-up of China’s nuclear arsenal, which will rival the size and diversity of the US and Russian stockpiles over the next decade, and comes as Russian president Vladimir Putin of Russia has threatened to use nuclear weapons in Ukraine.

Biden approved the revised strategy – called the Nuclear Employment Guidance – in March, according to the Times, but an unclassified notification of the policy change has not yet been presented to Congress.

After years of nuclear arms reduction efforts, the administration has been signaling willingness to expand the US arsenal to counter China and Russia’s nuclear strategies more recently. In February, the US warned allies that Russia could be planning to put a nuclear weapon into space.

On Tuesday, the Times reported that two senior administration officials had earlier been permitted to allude to the revision in US nuclear strategy without disclosing its existence.

In June, Pranay Vaddi, a senior director of the National Security Council, warned that “absent a change” in nuclear strategy by China and Russia, the US was prepared to shift from modernization of existing weapons to expanding its arsenal.

Vaddi also alluded to the highly classified document, saying it emphasized “the need to deter Russia, the PRC [People’s Republic of China] and North Korea simultaneously”.

That comes as the last major nuclear arms control agreement with Russia, New Start, that sets limits on intercontinental-range nuclear weapons, expires in early 2026 with no subsequent agreement in place.

China and Russia are now more politically and economically aligned. Last month, Chinese and Russian long-range bombers patrolled together near Alaska for the first time and held live-fire exercises in the South China Sea.

The second administration official permitted to refer to the document, Vipin Narang, an MIT nuclear strategist who served in the Pentagon, said earlier this month that Biden had “issued updated nuclear weapons employment guidance to account for multiple nuclear-armed adversaries” and for “the significant increase in the size and diversity” of China’s nuclear arsenal.

“It is our responsibility to see the world as it is, not as we hoped or wished it would be,” the Times quoted Narang as saying. “It is possible that we will one day look back and see the quarter-century after the cold war as nuclear intermission.”