Notifications for the sale of other weapons systems, including large, sophisticated aerial drones, land-based Harpoon anti-ship missiles and underwater mines, to deter amphibious landings, have yet to reach Capitol Hill, but these were expected soon, the sources said.
A State Department Spokesman said of the arms sales to Taiwan plan: "As a matter of policy, the United States does not confirm or comment on proposed defense sales or transfers until they are formally notified to Congress."
Chinese Foreign Ministry Spokesman Zhao Lijian said US arms sales to Taiwan severely damaged China's sovereignty and security interests, urging Washington to clearly recognize the harm they caused and immediately cancel them.
"China will make a legitimate and necessary response according to how the situation develops," Zhao told reporters in Beijing, without elaborating.
Congressional backing for Taiwan
The US Senate Foreign Relations and House of Representatives Foreign Affairs committees have the right to review, and block, weapons sales under an informal review process before the State Department sends its formal notification to the legislative branch.
Lawmakers, who are generally wary of what they perceive as Chinese aggression and supportive of Taiwan, were not expected to object to the Taiwan sales.
Taiwan's Defense Ministry said it would comment only when there was formal notification of any arms sale.
Foreign Ministry Spokeswoman Joanne Ou said the government had not yet been formally notified.