Sgt. Andrew Oquendo, a Marine from Paterson, N.J., pauses during a security patrol last month in Khan Neshin, in Helmand Province, Afghanistan. A new report by the top commander in Afghanistan detailing the deteriorating situation there confronts President Barack Obama with the politically perilous decision of whether to deepen American involvement in the eight-year-old war amid shrinking public support at home.

Washington ? The top U.S. commander for Afghanistan called the situation there “serious” but salvageable, in a sobering assessment issued Monday that is expected to pave the way for a request for more American troops, funds for Afghan forces and other resources. White House and Pentagon officials, while welcoming the assessment, cautioned that there is no guarantee such requests would be met.

The report by Gen. Stanley McChrystal, who has been tasked by President Barack Obama to implement a revitalized strategy for the war in Afghanistan, concludes that the Taliban insurgency in the country is stronger than previously realized, according to senior Pentagon and administration officials familiar with McChrystal’s thinking.

To tackle the problem, McChrystal believes above all that the ranks of Afghan soldiers and police must be increased, and that they must be trained more quickly, the officials said. That training is expected to require more U.S. and allied forces, although the assessment did not provide specific requests.

“The situation in Afghanistan is serious, but success is achievable,” McChrystal said in a statement. He added that progress will demand a revised strategy, greater “resolve” and “unity of effort” by the NATO-led multinational force.

Although the assessment, which runs more than 20 pages, has not been released, officials familiar with the report have said it represents a hard look at the challenges involved in implementing Obama’s strategy for Afghanistan. The administration has narrowly defined its goal as defeating al-Qaida and other extremist groups and denying them sanctuary, but that in turn requires a sweeping counterinsurgency campaign aimed at protecting the Afghan population, establishing good governance and rebuilding the economy.

For instance, McChrystal thinks a greater push by civilian officials is vital to shore up local Afghan governments and to combat corruption, officials said. He is emphatic that the results of the recent Afghan presidential election be viewed as legitimate, but is also realistic in acknowledging that the goals of the government of Afghan President Hamid Karzai and the coalition are not always as closely aligned as they could be, they said.

Separately, officials said, McChrystal’s assessment finds that U.S. and other NATO forces must adopt a less risk-averse culture, leaving bases and armored vehicles to pursue insurgents on foot in a way that minimizes Afghan civilian deaths.

The appraisal comes amid declining U.S. public support for the war and growing tension between U.S. commanders in need of resources and a White House wary of committing to fresh troops. It echoes recent gloomy statements by top military officials such as Adm. Michael Mullen, chairman of the Joint Chiefs of Staff, that the conflict is “deteriorating” and that the Taliban is far more sophisticated than it was just a few years ago.