Trade topped the agenda at a meeting of provincial premiers and U.S. governors in Washington Saturday afternoon.

It was the first time the premiers' organization, the Council of the Federation, met with the National Governors Association.

Saskatchewan Premier Brad Wall, chair of the Canadian group, and Ontario Premier Dalton McGuinty emphasized cross-border trade.

"We have the single largest trading relationship in the world, over $1.6 billion going back and forth across our border every single day," McGuinty told CBC News. "Ontario and Michigan do $60 billion worth of business every year."

Added Wall, "Thirty-six states here in the union have Canada as their No. 1 export market. Seven million jobs in this country [are] tied directly to trade with our country."

Electricity and green technologies were also on the agenda.

Quebec Premier Jean Charest promoted his province's green hydro power. "I'm chief salesman for Quebec and Quebec is hydro," Charest told CBC News.

Wall said the premiers are worried that U.S. Environmental Protection Agency measures to regulate carbon emissions could hurt Canadian manufacturers.

All the provincial premiers are on the trip except those from Alberta and British Columbia. Newfoundland and Labrador is represented by acting premier Kathy Dunderdale, as Premier Danny Williams is recovering from heart surgery in Florida.

With files from The Canadian Press