China has reiterated its position that it will not participate in nuclear negotiations with the United States and Russia, insisting its straightforward stance on the matter.

Chinese foreign ministry spokesperson Zhao Lijian told reporters that the U.S. was "neither serious nor sincere" in the proposed talks and would rather respond to Russia's call for an extension to the current New START treaty restricting nuclear warhead numbers.

The administration of U.S. President Donald Trump has requested that China engage in negotiations on a successor to the New START treaty that caps the American and Russian nuclear inventory – the two superpowers of the Cold War period.

"China's objection to the three-way arms control deal is very clear, and the U.S. knows it very well," Marty Johnson of The Hill quoted Zhao as saying, per an Associated Press report. The U.S., however, is persistent on the issue and has even distorted China's position, Zhao said, according to the report.

The U.S. and Russia – still the biggest nuclear-armed nations – met in Vienna at the end of June to start work on extending the New START treaty that was agreed upon in 2010 and is set to expire in February.

China has maintained that it will not participate in the discussions with Moscow and Washington on slashing its nuclear warhead inventory. However, Zhao seemed to hold open the door to some form of talks saying Washington needed to make conditions for other nuclear-powered states to join in disarmament negotiations.

The New START establishes several conditions, including reducing the number of deployed nuclear weapons the U.S. and Russia can possess at 1,550 each and limiting the deployment of such weapons that can launch the nuclear warheads. The deal also creates a validation program that features 18 on-site inspections a year.

Fu Cong, the director-general of the foreign ministry's arms control division, on Wednesday called the U.S. demand unrealistic because China has a much smaller nuclear arsenal compared to the U.S. and Russia. By inviting the country to participate, the U.S. is making a pretext to withdraw from the discussions without replacing the treaty, Cong disclosed.

Currently, China's military has far fewer nuclear warheads than either Russia or the U.S., both of which have around 5,000 nuclear warheads apiece. In comparison, it is projected that China only has around 320, the Stockholm International Peace Research Institute said, which means the U.S. would be required to scrap over 4,500 warheads from its current stockpile to match that of China.