"We firmly oppose the US side signing the 'Taiwan Travel Act' and have lodged stern representations with the US side…. The 'Taiwan Travel Act' sends out very wrong signals to the 'pro-independence' separatist forces in Taiwan," Lu said in a statement.
China has repeatedly stated that some clauses of the act, though not legally binding, severely violate the "One-China" principle and the three joint China-US communiques, the diplomat stressed.
"We urge the US side to correct its mistake, stop pursuing any official ties with Taiwan or improving its current relations with Taiwan in any substantive way, and handle Taiwan-related issues properly and cautiously so as to avoid causing severe damage to the China-US relations and cross-Straits peace and stability," the spokesman concluded.
On Friday, US President Donald Trump signed Taiwan Travel Act that seeks to stimulate visits between officials from Taiwan and the United States.
China has also expressed opposition to US contacts with Taiwan, the independence of which is not recognized by Beijing as it regards the island as its territory.