U.S. Defense Secretary Robert Gates is in Afghanistan to discuss efforts to stem continuing violence caused by an apparently resurgent Taliban. VOA's Al Pessin is monitoring the trip from the Pentagon.

Secretary Gates flew into Kabul for meetings on Tuesday with U.S. and NATO commanders and senior Afghan officials. The secretary says the allies need to find a way to maintain gains made in recent years and stop the violence.

"I am not worried about a backslide [of violence] as much as I am how we continue the momentum going forward," Gates said. " I think that one of the clear concerns that we all have is that the last two or three years there has been a continuing increase in the overall level of violence."

Secretary Gates spoke to reporters during a stop in Africa.

The NATO alliance has taken over responsibility for security in Afghanistan, but the United States is the largest troop contributor to the NATO force. And other U.S. forces continue to conduct counter-insurgency operations outside the NATO command in some parts of the country.

In addition to issues related to the Taliban, U.S. officials are concerned about indications that al-Qaida may be trying to resume its activities in Afghanistan. But Secretary Gates says he has "not heard much" about any increase in foreign fighters in the country. Officials have also expressed concern about insurgents' ability to operate in Pakistan near the Afghan border, and whether that situation might get worse, rather than better, because of Pakistan's political instability.