America's global allies seized on President Barack Obama's plan for an Afghan troop surge as a galvanizing call to action, pledging 5,000 new NATO troops and calling for unity in the face of flagging support for the drawn-out conflict.

But there were also warnings of caution, with other countries and observers urging broader solutions to the Afghan problem -- and reports of condemnation and threats from the Taliban militants the troop surge is aimed at neutralizing.

Obama on Tuesday said America would commit 30,000 more troops to join its force of 65,000 in Afghanistan, while setting a goal of starting to bring forces home by July 11.

The move prompted a NATO announcement Wednesday of at least 5,000 more non-U.S. troops in addition to the 42,000 personnel already in the country.

Among NATO allies, British Prime Minister Gordon Brown, Australia's Kevin Rudd and French President Nicolas Sarkozy all expressed their backing for Obama's plan, without detailing any individual pledges of extra troops.

"As the U.S. increases its commitment, I am confident that the other allies, as well as our partners in the mission, will also make a substantial increase in their contribution," said NATO Secretary General Anders Fogh Rasmussen.

"Taken together, the new force contributions from across the Alliance, as well as the new approach agreed by all the ISAF (International Security Assistance Force) countries, will help create a new momentum in the mission in 2010."

Rasmussen called Obama's decision to send an additional troops in Afghanistan "a broader political strategy for success."

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.

"I call on all our allies to unite behind President Obama's strategy. Britain will continue to play its full part in persuading other countries to offer troops to the Afghanistan campaign," Brown said in a statement.

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."

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.

Afghanistan, in a statement released via NATO's International Security Assistance Force, said it welcomed the troop surge and timetable for withdrawal.

"Afghanistan hopes that the increase in the U.S. troops will help further protect Afghan people and enhance security in the country," it said.

"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 coordiantion 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.

"India is not complaining at all and we do not wish to be seen as part of the problem," junior foreign minister Shashi Tharoor told reporters, according to the Agence France-Presse news agency.

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 Yousuf Ahamdi, 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.

In his speech, Obama said it was in the "vital national interest to send an additional 30,000 U.S. troops to Afghanistan" next year and that a drawdown would occur beginning in July 2011.

About 68,000 U.S. troops already are in Afghanistan, bolstered by around 50,000 troops from 42 nations, including all 28 NATO members.

The nine-year war 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.

The U.S. State Department said it was tripling the number of civilian staff deployed to Afghanistan and plans to have 974 staff members there by early next year.

In his speech, Obama emphasized that the U.S. troop commitment in Afghanistan was not open-ended, saying, "the nation that I am most interested in building is our own."