HONG KONG (REUTERS) - China's ZTE Corp said on Friday (April 20) that a ban on the sale of parts and software to the company was unfair and threatens its survival, and vowed to safeguard its interests through all legal means.

The United States this week imposed a ban on sales by American companies to ZTE for seven years, saying the Chinese company had broken a settlement agreement with repeated false statements - a move that threatens to cut off its supply chain.

"It is extremely unfair to ZTE and we cannot accept it!" China's second-largest telecoms equipment-maker said in a statement.

"Refusal orders will not only seriously endanger the survival of ZTE, but also hurt the interests of all ZTE's partners, including a large number of US companies."

ZTE said it regards compliance as the cornerstone of its strategy, adding it invested US$50 million (S$65.61 million) in export control compliance projects in 2017 and plans to invest more this year.

The ban has ratcheted up tensions between China and the United States at a time when they have already threatened each other with tens of billions of dollars in tariffs, fanning worries of a full-blown trade war.

In China, there has been a patriotic backlash with an outpouring of support for ZTE on social media and most domestic newspapers have chosen to put the lion's share of the blame for ZTE's troubles on the country's heavy reliance on foreign semiconductors.

Trade in ZTE shares has been suspended since Tuesday. As of Monday's close, they were worth some US$19 billion.