The U.S. has delayed a decision about duties on softwood lumber imports from Canada as the two nations remain at an impasse in a long-simmering spat.

The U.S. Department of Commerce will postpone its final determination for anti-dumping and countervailing duties on Canadian softwood lumber until Nov. 14, the department said Monday in an emailed statement. The decision was initially expected in the first week of September.

“I remain hopeful that we can reach a negotiated solution that satisfies the concerns of all parties,” Commerce Secretary Wilbur Ross said in the statement. “This extension could provide the time needed to address the complex issues at hand and to reach an equitable and durable suspension agreement.”

The delay comes as Canada and the U.S. are locked in a dispute over softwood lumber, a conflict that has caused intermittent friction for years. Tensions escalated in April when the Trump administration imposed preliminary countervailing duties of as much as 24 percent on Canadian imports. Additional duties of as much as 7.7 percent followed in June.

Prospects for an accord have faded, according to some analysts. Speculation had swirled that the countries may resolve their difference before talks this month aimed at renegotiating the North American Free Trade Agreement.

Last week, Canada’s Ambassador to the U.S., David MacNaughton, said the country is prepared to sue the U.S. if trade negotiations fail.

“That window to really get a deal done is rapidly closing,” Dan Ujczo, an international trade and customs lawyer with Dickinson Wright’s Ohio office, said by phone earlier on Monday. “Once the Nafta modernization started, they’re really taking more of a backseat on this issue.”