Kabul ? The Afghan government was holding secret talks with the Taliban’s No. 2 when he was captured in Pakistan, and the arrest infuriated President Hamid Karzai, according to one of Karzai’s advisers.

The detention of Mullah Abdul Ghani Baradar — second in the Taliban only to one-eyed Mullah Mohammed Omar — has raised new questions about whether the U.S. is willing to back peace discussions with leaders who harbored the terrorists behind the Sept. 11 attacks.

Karzai “was very angry” when he heard that the Pakistanis had picked up Baradar with an assist from U.S. intelligence, the adviser said. Besides the ongoing talks, he said Baradar had “given a green light” to participating in a three-day peace jirga that Karzai is hosting next month.

The adviser, who had knowledge of the peace talks, spoke on condition of anonymity because of their sensitivity. Other Afghan officials, including Abdul Ali Shamsi, security adviser to the governor of Helmand province, also confirmed talks between Baradar and the Afghan government. Several media reports have suggested that Baradar had been in touch with Karzai representatives, but these are the first details to emerge from the discussions.

Talking with the Taliban is gaining traction in Afghanistan as thousands of U.S. and NATO reinforcements are streaming in to reverse the Taliban’s momentum. That has prompted Pakistan and others to stake out their positions on possible reconciliation negotiations that could mean an endgame to the eight-year war.

Officials have disclosed little about how Baradar was nabbed last month in the port city of Karachi. The Pakistanis were said to be upset that the Americans were the source of news reports about his arrest.

The capture was part of a U.S.-backed crackdown in which the Pakistanis also arrested several other Afghan Taliban figures along the porous border between the two countries, after years of being accused by Washington of doing little to stop them.

Far from expressing gratitude, members of Karzai’s administration were quick to accuse Pakistan of picking up Baradar either to sabotage or gain control of talks with the Taliban leaders.

Whatever the reason, the delicate dance among Karzai, his neighbors and international partners put the debate over reconciliation on fast forward.

Top United Nations and British officials emphasized last week that the time to talk to the Taliban is now. The Afghan government, for its part, has plans to offer economic incentives to coax low- and midlevel fighters off the battlefield. Another driving force is President Barack Obama’s goal of starting to withdraw U.S. troops in July 2011.

The United States, with nearly 950 lives lost and billions of dollars spent in the war, is moving with caution on reconciliation.

At a breakfast meeting in Islamabad last week, Karzai said he and his Western allies were at odds over who should be at the negotiating table. Karzai said the United States was expressing reservations about talks with the top echelon of the Taliban while the British were “pushing for an acceleration” in the negotiation process.

“Our allies are not always talking the same language,” he said.

Karzai said overtures to the Taliban stood little chance of success without the support of the United States and its international partners. He says his previous attempts to negotiate with insurgents were not fruitful because “sections of the international community undermined — not backed — our efforts.”