BEIJING -- A Chinese mainland spokesperson Friday reiterated the country's opposition against any official and military contact between the United States and Taiwan.

The Taiwan issue, vital for China's sovereignty and territorial integrity, remains the most important and sensitive issue between China and the United States, said Ma Xiaoguang, spokesperson for the Taiwan Affairs Office of the State Council.

Ma was commenting on the US National Defense Authorization Act for Fiscal Year 2019, passed by the US Senate on Aug 1, which endorses strengthening defense ties with Taiwan.

Bringing in foreign interference in cross-Straits issues will only lead to more tension and unrest in the region and further complicate cross-Straits relations, Ma said.