The G20 has called for an outline deal in the talks -- launched in Doha in 2001 with the goal of helping poor countries prosper through trade -- to be reached by the end of the year.
"To complete Doha in 2010, I'm not very optimistic. I don't think it will happen," Rachid Mohamed Rachid said. "We have to get to a starting point before mid-year, and the window is closing."
"It's obvious that with unemployment in the United States and Europe, it is going to be tougher to have discussions on free trade," he told Reuters at the World Economic Forum in the Swiss resort of Davos.
The Doha talks have been stalled over U.S. demands that major emerging economies like China, Brazil and India open up their markets more in exchange for cuts in farm subsidies and agricultural and industrial tariffs that the United States is being asked to make.
Rachid said Pascal Lamy, the director-general of the World Trade Organization, hoped by the end of March to set a timetable for completing the talks.
"We are now at the end of January and we are not seeing any signals," Rachid said. "Where we left it last year... we were waiting for a signal of engagement from United States."
Brazil's foreign minister said that Doha negotiators should learn from last month's Copenhagen climate summit. Although the minimal, non-binding accord at Copenhagen disappointed nearly all participants, the talks did avoid a complete breakdown.
"We did have a basic accord among a large number of countries because there was political courage and because the leaders involved themselves directly," Celso Amorim told reporters in Geneva.
He suggested Lamy should select half a dozen key issues in the Doha negotiations for leaders to resolve during a summit of the Group of 20 rich and emerging nations.
"I still think it's possible to do a deal if there's enough political courage," Amorim said. Asked whether that would be in 2010, he replied: "Political courage can come any time."
Additional reporting by Jonathan Lynn in Geneva, Editing by Lin Noueihed