Chinese Foreign Ministry spokeswoman Hua Chunying said on Monday that Beijing’s resolute opposition to US arms sales to Taiwan was clear and consistent.
"We hope the US side fully recognizes the high sensitivity and serious harmfulness of its sales to Taiwan," she said.
The official called on Washington to abide by the 'One China' policy and "cease Taiwan arm sales" in order to preserve Sino-US relations as well as peace and stability in the Taiwan Strait.
The comments, which came one day after US Secretary of State Rex Tillerson ended a visit to Beijing, followed reports in US media that Trump's government was preparing a large-scale arms package for Taiwan.
There is contact between Taiwan and the Trump administration on the arms sale issue, but a specific request list has not been drawn up for this year, though there are pending requests from last year, according to Defense Ministry official Wu Pao-kun.
The United States is Taiwan's only major political ally and sole arms supplier, and weapons sales to Taiwan have repeatedly upset Beijing, which sees Taiwan as part of its territory.
President Donald Trump and China's President Xi Jinping subsequently smoothed over the dispute in a phone call in which the US leader reiterated Washington's adherence to the 'One China' policy, which nominally acknowledges Beijing's claim without recognizing it.
Tillerson told President Xi on Sunday in Beijing that Trump anticipated a meeting "soon."