In a strong show of unity, President Bush and NATO's secretary general exchanged words of welcome and expressions of gratitude Wednesday.

President Bush said America will never forget the help it's getting from its NATO allies in a "time of great need."

The president welcomed Lord Robertson to the White House with thanks for what he calls acts of "great friendship."

NATO members are sharing intelligence, coordinating law enforcement and cracking down on the financing of terrorist organizations. Some are providing logistic support to military operations and others have offered to fight if necessary. British forces have already joined U.S. attacks on Afghanistan.

The alliance is also sending Airborne Warning and Control System (AWACS) surveillance planes to patrol American shores so similar U.S. planes can deploy for the air campaign. They are expected to arrive Friday.

Joining Bush before cameras in the Rose Garden, Robertson voiced confidence the American-led coalition will prevail over terror.

"These terrorists are not 10 feet tall, they are not insuperable. They're not unvanquishable. But we are, and we can win, and we certainly will win," Robertson said, describing the terrorists as "the most evil criminals of our age."

In a rare show of humor since the attacks, the president complimented Robertson by saying, "He's a good Scotsman, like many Americans are. He could have been a Texan, it seems like to me, because he is courageous, open, forthright, and not afraid to take a stand and to do what's right for freedom."

Robertson responded that Bush would have made a good Scotsman.

The Associated Press contributed to this report.