Afghan officials say they have launched an expanded effort to spy on their own police and army recruits, an acknowledgment that previous measures designed to reduce insurgent infiltration in the country’s security services have failed.

The steps come amid a spate of “insider” attacks that have shaken the U.S.-Afghan military partnership during a stage of the war that hinges on close partnership between the two forces.

Nine U.S. troops have been killed by their Afghan counterparts in the past 12 days. They are among 40 coalition service members who have died in insider attacks this year. President Obama, in his most extensive comments to date on the issue, said Monday that his administration is “deeply concerned about this, from top to bottom.”

The Afghan measures include the deployment of dozens of undercover intelligence officers to Afghan security units nationwide, increased surveillance of phone calls between Afghan troops and their families, and a ban on cellphone use among new recruits to give them fewer opportunities to contact members of the insurgency, Afghan officials say.

The initiatives appear aimed at addressing U.S. criticism that the Afghan security forces are not doing enough to ferret out insurgents within their ranks. The top U.S. military official, Gen. Martin Dempsey, was in Kabul on Monday for consultations on the matter, and Obama said he would soon be “reaching out” to Afghan President Hamid Karzai.

“Soldiers must feel that they are under the full surveillance of their leadership at all levels,” the Afghan army chief of staff, Gen. Sher Mohammad Karimi, said in an interview after meeting with Dempsey and other U.S. commanders. “Initially, it will have a negative impact on morale, but we have to do something. We have to look seriously at every individual.”

Coalition policy changes

NATO has taken steps in recent days to try to limit the attacks, which Taliban leader Mohammad Omar has described as an integral part of his group’s strategy.

Across Afghanistan, service members have been asked to keep their weapons loaded at all times, according to coalition officials. NATO has also activated an existing program, dubbed “Guardian Angels,” in which coalition troops whose only job is to watch their fellow troops attend meetings with Afghan officials prepared to quell an insider attack if one should occur.

Obama said U.S. forces are “seeing some success when it comes to better counterintelligence, making sure that the vetting process for Afghan troops is stronger.” But, he added, “obviously, we’re going to have to do more, because there has been an uptick over the last 12 months on this.”

Insider attacks are a relatively new aspect of the war, having emerged as a major problem for the United States and its allies only in the past several years. There have been more deaths from insider attacks in 2012 than in any other year of the war, and they have accounted for 13 percent of all NATO fatalities this year.

Tight choreography

As U.S. troops begin to withdraw, the attacks threaten to upend plans for a transition from foreign to Afghan control of security that will require tight choreography between the two forces.

But the new Afghan measures carry their own peril, with the potential to further alienate rank-and-file troops and would-be recruits at a time when the government is struggling to build loyalty.

Afghan officials say that 176 intelligence officers were assigned to army battalions last week and that most will remain undercover. They join hundreds of others who are tasked with spotting wayward troops before they carry out “green-on-blue” attacks.

Karimi said Afghanistan would also reinforce a vetting procedure that had never been properly employed, allowing cursory or no background checks for new recruits.

A number of the attacks this year were carried out by individuals who faced little scrutiny in getting access to joint U.S. and Afghan bases. This month, an unvetted 15-year-old “tea boy” who had been living on a police base in Helmand province killed three U.S. Marines while they exercised.

“We had a policy for recruiting from Day One, but it hasn’t been implemented. We needed too many people,” Karimi said. “When you need 12,000 people each month — it’s a number so high that we couldn’t implement the policy,”

Now that the security forces are approaching their targeted recruitment levels, officials said, they can concentrate on ensuring that the right soldiers and police have entered the ranks. That means paying close attention to what recruits do after enlisting.

“Whenever a new recruit goes on leave, we have reconnaissance following that person to make sure he doesn’t pose a threat,” said Maj. Gen. Abdul Hamid, the top Afghan army official in Kandahar.

The Afghan efforts represent an expansion of earlier attempts to curb insider killings. Earlier this year, for instance, soldiers were forced to move their families back from Pakistan or quit their jobs. Many infiltrators are thought to have received training from insurgent groups in Pakistan.

Karimi on Monday briefed Dempsey, the chairman of the U.S. Joint Chiefs of Staff, and Gen. John R. Allen, the top U.S. commander in Afghanistan, on Afghanistan’s plans for the expanded counterintelligence measures.

Dempsey has long complained about the flawed Afghan vetting process, telling reporters in March that the problem of insider attacks would be solved only “when they have the same vetting as we do.”

He sounded an encouraging note after his meeting Monday with Karimi. “In the past, it’s been us pushing on them to make sure they do more,” Dempsey said. “This time, without prompting, when I met General Karimi, he started with a conversation about insider attacks.”

Cultural clashes

Not all attacks have been the result of insurgent infiltration, and NATO officials have said that most stem from personal disputes. Afghan military officials say they have asked their U.S. and other NATO counterparts to better educate their troops in local traditions and culture to help reduce the potential for conflict.

“If a U.S. soldier says something against our tradition, it makes Afghan soldiers upset and could even cause an attack,” said Feda Wakil, the chief of staff for recruitment at the Afghan National Police. “We always tell NATO that the troops are not arriving with enough knowledge. They are learning from Afghans overseas who do not truly understand our culture.”

Afghan officials say they have also asked the Americans for help in tightening standards within the Afghan forces. The army says it wants polygraph machines and interceptors to monitor phone calls. Police officials have asked for more biometric equipment, which they say will help them check the criminal records of potential recruits.

“If we can’t reduce the number of these attacks to zero, we should at least minimize the number,” Karimi said.

Javed Hamdard and Sayed Salahuddin contributed to this report.