The US Strategic Command (Stratcom) advised lawmakers about Beijing’s new powerful facilities, which boast fast breeder reactors. The first fast breeder reactor is scheduled to become active in 2023.
Navy Admiral Charles Richard, commander of the US Strategic Command, delivered the news to the Senate Armed Services Committee on Tuesday.
He said: “With a fast breeder reactor, you now have a very large source of weapons grade plutonium available to you, that will change the upper bounds of what China could choose to do if they wanted to, in terms of further expansion of their nuclear capabilities.”
Stratcom supervises the US nuclear arms stockpile.
Concerns were raised in the US amid tensions despite there being no evidence Beijing intends to use large amounts of plutonium to manufacture weapons.
China asserted its nuclear program is not intended for belligerent purposes.
However, relations between the two countries have been under pressure over links with Taiwan, which China claims as part of its territory.
Earlier this month, the US State Department decided to deepen its relations with Taiwan, prompting a stark warning from Beijing.
During a press conference, Chinese Foreign Ministry spokesperson Zhao Lijian told Washington “not to play with fire on the Taiwan issue”.
He continued: “Immediately stop any form of US-Taiwan official contacts, cautiously and appropriately handle the matter, and not send wrong signals to Taiwan independence forces so as not to subversively influence and damage Sino-US relations and peace and stability across the Taiwan Strait.”