After two years, and multiple attempts to acquire a prized copper-and-gold deposit in Serbia, Lundin Mining Corp. (LUN.TO) said it won’t raise its offer for Nevsun Resources Inc. (NSU.TO) in the face of a competing bid from China.

The Toronto-based company said it doesn’t intend to amend any of the terms of its tender offer for Nevsun, despite a higher, US$1.41 billion bid from Zijin Mining Group Co., according to a release dated Sept. 6.

“Lundin Mining continues to pursue strategic growth opportunities,” Lundin said in the statement. “Our portfolio of high-quality long-life, mines enables us to remain disciplined to our investment criteria and rigorous in our allocation of capital to deliver superior shareholder returns.”

Lundin’s attempted to acquire a stake in Nevsun’s Timok deposit dates back to 2016, when the project was majority-owned by Freeport-McMoRan Inc., in partnership with Reservoir Minerals Inc. The attempt was scuppered when Reservoir exercised its right of first refusal, funded by Nevsun as part of its takeover of Reservoir.

Further attempts by Lundin followed, including a takeover play with Euro Sun Mining Inc. announced in May. Last month, Lundin’s outgoing Chief Executive Officer Paul Conibear told analysts that five successive takeover proposals were rejected by Nevsun since February of this year. In July, the company formally launched a hostile takeover bid. Earlier this week, Zijin stepped in as a white knight, offering $6 per share in cash, compared to Lundin’s $4.75 a share bid.

Billed as one of the world’s best undeveloped copper projects, Timok would allow Lundin to replace production lost from its exit from the Democratic Republic of Congo. Earlier this year, Lukas Lundin, who runs the billionaire Swedish-Canadian family’s commodities empire with his brother, said he was looking to spend as much as US$3 billion on a new industrial-metal asset, saying copper “might be the easiest asset to work with.”

Rising demand for electric vehicles and power generation has tightened global copper supply, leading to forecasts of long-term deficits. That said, prices have fallen this year as trade tensions and the recent emerging market crisis weigh on the outlook for global growth and strengthen the U.S. dollar.