WASHINGTON - Sen. John Kerry declared Monday that he opposed sending more U.S. troops to Afghanistan unless the government and military there improve their performance, and said the top American military commander in the country was moving "too far, too fast" in recommending an increase of 44,000 more troops.

Kerry, D-Mass., spoke in what was billed as a major address at the Council on Foreign Relations, after he returned from a fact-finding trip to Afghanistan. His remarks have particular weight because he heads the Senate Committee on Foreign Relations and is a key ally of President Barack Obama's.

In his address, Kerry seemed to search for a middle ground between some on the right who have called for a troop buildup and others on the left who have advocated a military drawdown and a tight focus on counterterrorism.

"A narrow mission that cedes half the country to the Taliban could lead to civil war and put Pakistan at risk," Kerry said. But he also argued against a troop surge, unless three conditions could be met: better Afghan governance, a bigger civilian development effort and a supply of reliable Afghan security forces to work with American troops.

He said Gen. Stanley McChrystal's plan, which calls for 44,000 troops to carry out a counterinsurgency campaign, "reaches too far, too fast."

"We do not yet have the critical guarantees of governance and development capacity," Kerry said. He added that he also had "serious concerns about the ability to produce effective Afghan forces to partner with" in military operations.

Kerry said, however, that "under the right circumstances, if we can be confident that military efforts can be sustained and built upon, then I would support the president" sending additional troops.

James Dobbins, who served as a special envoy to Afghanistan during the Bush administration and is now at the Rand Corp., said Kerryhad made many "sensible" points in the speech but that he found the conclusion unsatisfactory.

"The argument seems to be that we're not going to send more troops until we start winning - which seems to me to be an inversion of the usual sequence," he said.

Stephen Biddle, a senior fellow for defense policy at the Council on Foreign Relations, said Kerry's tone differed from that of McChrystal, whose recent assessment warned that the war could be lost without an infusion of troops. But Biddle noted that the two men's analyses had a lot of overlap.

"They both think governance reform is essential, they both think economic development is essential, they both think the security of the people of Afghanistan is the center of gravity," said Biddle, who has advised McChrystal. "Both think the Afghan security forces should be expanded and we should put an Afghan face on the war."

Kerry called for NATO countries and the United Nations to do more to support development in Afghanistan and said the U.S. civilian presence in the country was "disgraceful compared to what it ought to be." He said Secretary of State Hillary Rodham Clinton understood the urgency of dispatching civilians to help improve governance and provide services. "They're trying to find people as fast as they can," he said.

Deputy Secretary of State Jack Lew told reporters Monday that almost 300 U.S. agronomists, diplomats, legal experts and others had been sent to Afghanistan since March as part of Obama's "civilian surge," bringing the total there to 603. The administration expects to have almost all its total commitment of 974 civilians on the ground by the end of the year, Lew said.

But Lew said that only 157 of the U.S. civilians are working outside Kabul, the capital, because some areas have not yet been secured by the military and two new U.S. consulates have not yet been completed.