United Nations (CNN) -- U.N. Secretary General Ban Ki-moon welcomed U.S. President Barack Obama's plan to deploy 30,000 more troops to Afghanistan.
In a written statement, Ban praised Obama's aim to "balance military and civilian efforts" and focus on strengthening institutions and security forces in Afghanistan, noting that it would be a long-term but essential process.
Obama's decision will bring the total number of U.S. troops in Afghanistan to nearly 100,000. In part, the new 18-month initiative against the Taliban seeks to accelerate the training of Afghan national security forces. As early as July 2011, troops would begin transferring responsibility to Afghan authorities.
However, U.S. Ambassador Susan Rice indicated "it is not the expectation" that all required Afghan security forces "will be trained within 18 months."
On Wednesday NATO Secretary-General Anders Fogh Rasmussen said on CNN's "Amanpour" program that the non-U.S. members of NATO intend to initially commit at least 5,000 more troops to Afghanistan "based on what we know now."
The additional units would bring NATO's contribution to the Afghan war to about 47,000 troops. The first pledges could be announced at a conference of NATO foreign ministers Thursday and Friday in Brussels, Belgium, the seat of the alliance, Rasmussen said.
In addition to the 28 NATO allies, 15 non-NATO members have contributed troops to the U.S.-led coalition. The largest contribution from those countries is from Australia, with 1,200 troops.
Australia's Kevin Rudd said his country welcomed the "credible" new U.S. strategy and pledged to "increase our police training and civilian development assistance" but did not outline any additions to its 1,550-strong deployment.
Gordon Brown, who earlier this week announced 500 extra British troops, said his country would press for more international military contributions and would use an international conference in London in January to map out how security will be handed back to Afghans.
Nicolas Sarkozy said France called on "all countries that want to help the Afghan people to adhere to it," saying its nearly 4,000 personnel there were focused on securing stability and training Afghan security forces.
Sarkozy said a meeting of NATO ministers this week and the London conference will "underscore the international community's unity."
Afghanistan, in a statement released via NATO's International Security Assistance Force, said it welcomed the troop surge and timetable for withdrawal.
"Afghanistan believes that setting a timetable for the reduction of the U.S. forces will pave the way for the growth of the Afghan security forces and the eventual self-reliance we seek."
Key U.S. regional ally Pakistan, which is facing its own struggle against Taliban militants, said it had taken "careful note" of Obama's announcement, but wanted to "ensure there would be no adverse fallout on Pakistan."
"Pakistan and the U.S. need to closely coordinate their efforts to achieve shared objectives. There is certainly the need for clarity and coordination on all aspects of the implementation of the strategy," a Foreign Ministry statement said.
India, which does not contribute troops to the International Security Assistance Force in Afghanistan but has provided more than $1 billion humanitarian and developmental assistance, offered muted approval.
Human Rights Watch said Obama's plan needed to strengthen civilian protection with a "clear strategy for combating corruption, removing warlords and holding rights violators accountable."
The human rights organization called the U.S. emphasis on rule of law in Afghanistan "long overdue" but said sufficient training of Afghan security was needed to "ensure basic human rights protections."
In Afghanistan, Obama's plan reportedly drew threats from the Taliban militants who will be fighting the reinforcements.
"Obama will witness lots of coffins heading to America from Afghanistan," Taliban spokesman Qari Yousef Ahmadi, speaking from an unknown location, told AFP.
"Their hope to control Afghanistan by military means will not become reality. The extra 30,000 troops that will come to Afghanistan will provoke stronger resistance and fighting," he added.
"They will withdraw shamefully. They cannot achieve their hopes and goals," the spokesman said.
The nine-year war in Afghanistan came on the heels of the September 11, 2001, attacks on the United States by al Qaeda, which had been given safe haven in Afghanistan by the Taliban government.
Nearly 3,000 people died in the attacks on New York and Washington. Since being overthrown in 2001, the Taliban have been trying to regain strength in Afghanistan as well as Pakistan.