The union told Reuters on Sunday that it will decide whether to attend a meeting with the company after holding two assemblies for its 2,500 members on Sunday and early on Monday. The company has proposed talks for Monday afternoon.
Escondida said on Friday that it had agreed to meet with the union and was offering better salaries, bonuses and benefits in response to workers' three main demands.
"We're sorry to say that all of that is just manipulation and deceit," the union told its members in a statement late on Saturday about the new proposal to end the strike, which has put pressure on global copper prices.
The union wants Escondida not to trim benefits in its existing contract, not to make shift patterns more taxing, and to offer the same benefits to new workers as existing ones.
BHP, which owns a 57.5 percent stake in the mine, did not immediately respond to requests for comment.