WASHINGTON - American trade experts say North American leaders meeting next week need to counteract a barrage of negative rhetoric about NAFTA on the U.S. campaign trail.

The American experts say all the talk from Democratic presidential hopefuls about reopening the trade deal is feeding into protectionist sentiments that are bad for everybody.

Both Hillary Clinton and Barack Obama have threatened to withdraw from the North American Free Trade Agreement if it isn't renegotiated to include protections for workers and the environment.

Jim Bacchus, a former executive at the World Trade Organization, says Canada is opposed to reopening the deal and the U.S. needs to be careful what it wishes for.

Jim Jones, former U.S. ambassador to Mexico,  says the reality is that NAFTA has increased trade and that most job losses in the United States in the last 15 years are the result of technological change.

Prime Minister Stephen Harper is meeting in New Orleans next week with U.S. President George W. Bush and Mexico's Felipe Calderon for their annual trilateral summit.