NATO Secretary-General Anders Fogh Rasmussen speaks during a joint news conference in Pristina May 21, 2010. REUTERS/Hazir Reka/Files

OTTAWA (Reuters) - The Taliban is stronger than NATO expected but the international coalition in Afghanistan will make progress both militarily and politically this year, NATO Secretary-General Anders Fogh Rasmussen said on Monday.

Thousands of U.S. troops are being deployed in the southern province of Kandahar, a Taliban stronghold, as part of a new counter-insurgency strategy. This month militants attacked Kandahar airfield and a big coalition base in Bagram.

“I think we have to be honest and say they seem to be stronger now than we had expected when the international operation started back in 2001,” Rasmussen told the Canadian Broadcasting Corp. in a phone interview.

“But we will continue our military operation and we will ... see momentum in 2010, first of all because we have increased the number of international troops significantly and secondly, because the political process will move in the right direction,” he said.

Afghanistan President Hamid Karzai has called a traditional gathering of elders to discuss the prospects of making peace overtures to some Taliban elements. It starts this Wednesday.

NATO could back this process by providing enough security, said Rasmussen. It was important that Kabul “can negotiate from a position of strength and this is the reason why we have to continue a determined military effort,” he added.

The Taliban announced an offensive from May 20 against the government, foreign forces and diplomats in Afghanistan in response to the plans for a Kandahar offensive.

“The Taliban know that we are now aiming right at their heartland ... and they will do what they can to fight back because they know that if they lose here, it will be a devastating blow,” said Rasmussen.

“But I also have to say that both the Kandahar and Bagram attacks were -- militarily speaking -- failures.” (Reporting by David Ljunggren; Editing by Frank McGurty)