WASHINGTON — American military officials are building a case to minimize the planned withdrawal of some troops from Afghanistan starting next summer, in an effort to counter growing pressure on President Obama from inside his own party to begin winding the war down quickly.

With the administration unable yet to point to much tangible evidence of progress, Gen. David H. Petraeus, who assumed command in Afghanistan last month from Gen. Stanley A. McChrystal, is taking several steps to emphasize hopeful signs on the ground that, he will argue, would make a rapid withdrawal unwise. Meanwhile, a rising generation of young officers, who have become experts over the past nine years in the art of counterinsurgency, have begun quietly telling administration officials that they need time to get their work done.

“Their argument,” said one senior administration official, who would not speak for attribution about the internal policy discussions, “is that while we’ve been in Afghanistan for nine years, only in the past 12 months or so have we started doing this right, and we need to give it some time and think about what our long-term presence in Afghanistan should look like.”

Defense Secretary Robert M. Gates signaled the military’s position recently when he said that the initial troop withdrawals next summer “will be of fairly limited numbers.” General Petraeus, who has kept a low profile for the past six weeks while conducting a countrywide assessment, is expected to amplify the message during the media offensive he will begin on Sunday, when he is to appear on the NBC News program “Meet the Press.” He is expected to say that the last of the 30,000 additional troops Mr. Obama ordered to Afghanistan last December will not arrive until later this month, and that the counterinsurgency strategy has not been given enough time to succeed.