Deal on Pakistan Supply Lines Not Expected During NATO Summit

American and Pakistani officials had expressed optimism last week that an agreement was imminent. Negotiators were narrowing their differences after three weeks of intense deliberations, they said, and it was hoped that an invitation for Pakistan to attend the summit would engender the goodwill needed to close the gap between the two sides .

The invitation was accepted, and Pakistan’s president, Asif Ali Zardari, arrived in Chicago on Saturday. But a deal on the supply lines remained elusive, and President Obama would not meet directly with Mr. Zardari without it, American officials said.

The supply lines, through which about 40 percent of NATO’s non-lethal supplies had passed, were closed in late November after 24 Pakistani soldiers were killed in American air strikes along the border between Afghanistan and Pakistan. The deaths capped a year of crises between the United States and Pakistan that put immense strain on the two countries’ already fragile relationship.

The failure to strike a deal on the supply routes ahead of the summit injects new tension into the relationship. “When NATO extended the invitation, we thought it would move the Pakistanis off the dime,” said a senior American official.

Without the deal, “it’s going to be really uncomfortable for” Mr. Zardari at the summit, the official said, speaking on the condition of anonymity because of the diplomatic nature of the talks.

American officials said the main sticking point was the amount NATO would pay for each truck carrying supplies from Karachi, on Pakistan’s Arabian Sea cost, to the Afghan border. Before the closure, the cost per truck was about $250. Pakistan is now asking for “upwards of $5,000,” another American official said.

Pakistan was also seeking an indemnity waiver in case American cargo was damaged, as well as more money to repair road damage caused by the heavy trucks transiting Pakistani highways.

“We’re not anticipating necessarily closing out those negotiations this weekend,” said Ben Rhodes, a deputy national security advisor, on Saturday evening during a briefing with reporters aboard Air Force One en route to Chicago.

Mr. Rhodes said the White House believes a deal will eventually be reached, but declined to say when it could be expected.

“It’s our sense that both sides want to get it done, it will get done,” he said. “But right now, we’re in a process of negotiation about how exactly that’s going to happen.”

Pakistan’s ambassador to the United States, Sherry Rehman, expressed similar sentiments in an interview with CNN on Friday, saying “there has been some movement forward.”

Ms. Rehman also said it was a sign of “good tidings” that Pakistan had allowed a few trucks to carry supplies to the American embassy in Kabul late last week.

But the senior American official said on Saturday that if a few trucks were allowed through in an effort to show good faith for a broader deal, it only further exasperated American officials who had believed they were on the brink of breaking the six-month impasse, the official said.

American officials said they have managed to work around the closure of the Pakistani supply routes by using a northern supply line throughCentral Asian countries.

But with the drawdown of forces from Afghanistan expected to accelerate sharply this year and into 2013, Washington is eager to reopen the Pakistani routes, which American officials hope will help bring down costs and alleviate pressure on the northern route.

There is also the issue of being dependent on a single supply route. The northern route was set up to diversify the NATO-led coalition’s supply lines, not simply shift the alliance’s dependence from Pakistan to Central Asian nations.