NEW DELHI – Recent moves by Afghanistan and Pakistan to improve their once-frosty relationship have prompted deep concern in other countries in the region and led some to consider strengthening ties to Afghan President Hamid Karzai’s political rivals.

The U.S. government considers the Afghan-Pakistan overtures essential to combating insurgencies wracking both nations. But India, Iran and Afghanistan’s northern neighbors fear that they are a step toward fulfilling Karzai’s desire to negotiate with Taliban leaders and possibly welcome some of them into the government.

These nations believe that Karzai’s plans could compromise their security and interests by lessening the influence of Afghanistan’s Tajik, Uzbek and Hazara ethnic minorities with whom they have cultivated close links, diplomats and government officials say.

The apprehension, voiced pointedly by senior Indian officials in interviews this week, has emerged as yet another challenge for the U.S. government as it seeks to encourage initiatives to stabilize Afghanistan while minimizing fallout on the already tense relationship between India and Pakistan.

In an attempt to assuage those concerns, the Obama administration’s special representative for Afghanistan and Pakistan, Richard Holbrooke, traveled Wednesday to meet with India’s national security adviser and foreign secretary. The chairman of the Joint Chiefs of Staff, Adm. Mike Mullen, arrived Thursday for two days of meetings with top military and civilian leaders.

One concern to the Indians is Karzai’s interest in reconciling with elements of the Taliban leadership. Because of the Taliban’s historic ties to Pakistan’s intelligence agency, Indian officials believe that such a move would give Pakistan new influence in Afghanistan.

Allowing the Taliban, which is dominated by ethnic Pashtuns, to have a role in the Afghan government is something “we don’t think is a very good idea,” a senior Indian government official said.