KABUL, Afghanistan -- Afghanistan's Taliban-led insurgency is likely to worsen this year as new NATO troops replace battle-hardened American forces in some areas and the government pushes ahead with an aggressive antidrug campaign, a senior US envoy said.
The warning by Richard A. Boucher, the assistant secretary of state for South and Central Asia, came after an uptick in attacks in recent weeks as spring weather melts snow on high mountain passes the rebels use.
Last year was the deadliest for rebel violence since US-led forces ousted the Taliban in 2001. Some 1,600 people, including 91 US troops, were killed. That was more than double the total in 2004.
''We will probably see a rise in violence this year as NATO spreads into areas in a more dense fashion, as the insurgents try to test the new forces [and] as the government takes on the narcotics traffickers in new areas," Boucher told reporters in Kabul.
He said the rebels ''certainly have the ability to continue doing what they are doing for a while and be very nasty."
NATO is assuming control gradually of security in Afghanistan from a US-led coalition. By midyear, NATO troops are set to take over volatile southern regions, and by September they are expected to control the entire country.
The United States will keep about 16,000 soldiers here, down from about 19,000 now, but they will be under NATO command. The British, the Dutch, and the Canadians have deployed thousands of soldiers in recent months.
Many Afghans believe the US drawdown indicates the start of a gradual withdrawal, but US officials suggested otherwise.
US Ambassador Ronald Neumann, speaking alongside Boucher, said the Taliban have the impression that with time, they will gradually wear out the patience of foreign governments to keep their troops deployed here.
''There was a Taliban leader who said to one of our folk that the coalition has all the clocks, but we have all the time," Neumann said. ''That is the way they tend to see the world, that they can outwait the foreigners."
But Boucher said US forces were going to stay.
''People are going to see us here for a long time to come," he said.
In the latest violence, insurgents fatally shot a Turkish road engineer and burned his body in Nimroz province Sunday, said Ghulam Dastagir Azad, the provincial governor. A purported Taliban spokesman, Mohammed Hanif, claimed responsibility.
In neighboring Helmand province Sunday, a firefight between a group of insurgents and police left one officer and a rebel dead, and two police wounded, said Mohanned Qasin, a local government chief.
Helmand is Afghanistan's main poppy-growing region. Yesterday Afghan antidrug forces raided Bahram Chah, which the Ministry of Interior described as a ''drug-trafficking town" near the border with Pakistan.
Some 165 pounds of opium resin were seized and one person was arrested, a ministry statement said. Afghanistan supplies nearly 90 percent of the world's opium and heroin, and some of the profits from the illicit business are believed to go to the Taliban.
The government, backed by hundreds of millions of dollars in US and British money, has launched a campaign to forcibly eradicate poppies in many areas -- a move that is believed to have prompted armed resistance from traffickers.