But key leaders of Afghanistan’s three largest ethnic minorities told The Wall Street Journal that they oppose Mr. Karzai’s outreach to the Taliban, which they said could pave the way for the fundamentalist group’s return to power and reignite civil war.

Mohammed Mohaqeq, a lawmaker and former warlord representing the 2.5-million-strong Hazara minority, endorsed Mr. Karzai in last year’s presidential race, contributing to his reelection.

“We feel betrayed by the president,” Mr. Mohaqeq says now. “It seems that what President Karzai pursues now is the Talibanization of Afghanistan. The only difference between him and the Taliban is that he sits in the presidential palace and the Taliban sit in the mountains.”