Berlin, Germany (CNN) -- NATO's secretary-general is confident that "all allies will step up to the plate" and provide more soldiers to the fight in Afghanistan after President Barack Obama announces his decision next week on an extra U.S. troop deployment.
"We are right now in the final phase of consultation and we all know that the Americans are the biggest troop contributors so it's quite natural that we wait for an American decision," Anders Fogh Rasmussen told CNN.
"I think it's of utmost importance for the alliance and certainly for our operation in Afghanistan that the allies follow suit once the Americans have made their decision."
Winning the fight against the Taliban and al Qaeda in Afghanistan and along the Afghan-Pakistan border has been one of President Obama's top foreign policy priorities, and the tenacity of the militants in war-torn southern and eastern parts of the country bordering Pakistan has underscored the importance of the international effort.
British Prime Minister Gordon Brown has said he is "optimistic" that other countries will contribute more troops to the mission in Afghanistan, and told Rasmussen in a letter recently that Cabinet ministers and senior officials recently met with 10 "key coalition partners" about increased troop commitments in 2010. He did not name the countries.
Rasmussen says it's "too early to speak about concrete troop numbers" but he is "sure that an additional number of troops will contribute to improvement of security in Afghanistan."
"I not going to announce any exact figure right now, but I have been in contact with allies and I feel confident that they will contribute an additional number of troops which is also essential for keeping the alliance in operation in Afghanistan. "
He said he is calling political leaders in the 43-country NATO-led fight and requesting more troops, efforts that have led to "some positive messages."
"The fact is that there is a strong feeling of solidarity within our alliance and I feel confident that this principle of solidarity will continue to be the basis of our operations in Afghanistan," he said.
President Obama will announce the U.S. troop strategy for Afghanistan in a speech Tuesday at West Point, the end of a long consultative process on how to proceed in the country, where the United States currently deploys 68,000 troops and the NATO forces another 45,000.
Obama has weighed several options for bolstering the American contingent, ranging from sending a few thousand troops to the 40,000 requested by Gen. Stanley McChrystal, the top U.S. military official in Afghanistan.
A defense official told CNN earlier this week that one of the options was to send about 34,000 more troops to Afghanistan. In this scenario, the military has planning under way to send three U.S. Army brigades, totaling about 15,000 troops; a Marine brigade with about 8,000 troops; a headquarters element of about 7,000; and between 4,000 and 5,000 support troops -- a total of about 34,000 troops.
Two U.S. military officials have told CNN that NATO countries would be asked to contribute more troops to fill the gap between the 34,000 the Pentagon expects Obama to send and the 40,000 McChrystal wants. The request is expected to come during a December 7 meeting at the alliance's headquarters in Brussels, Belgium.
NATO's Rasmussen said he doesn't "blame Americans that they have spent some time to go through all this because it is a very important decisions and its important that we get it right." One of the factors in making a decision was waiting for a conclusion to the Afghan presidential elections -- a "tough" stretch of time in what was a flawed electoral process.
"Now it has been concluded. We will take decisions on additional troops to Afghanistan. We will step up our endeavors within reconstruction. President Karzai has promised to fight corruption and drug trade," Rasmussen said. "So all in all you will see new momentum."
Rasmussen talked about the importance of training Afghan security forces and implementing a counter-insurgency approach where relations between military and civilian reconstruction people are deepened.
"I think that there is a broad consensus that we must prevail in Afghanistan -- to defend against terror and to prevent Afghanistan from being a terrorist base.
"If we left Afghanistan behind it could spread from Afghanistan and through central Asia and risks destabilizing neighboring Pakistan a nuclear power. So I think that there is a broad consensus that we stay committed until the job is finished and obviously that is not forever."
CNN's Paula Newton contributed to this report.