Defense Secretary Robert Gates, in his first speech as Pentagon chief, made an urgent call Sunday for NATO allies to live up to their promises to supply military and economic aid for Afghanistan, saying that failing to do so would be shameful.

And in a carefully worded rebuke, he used both humor and some pointed jabs to blunt Russia's sharp attack against U.S. foreign policy a day earlier.

In remarks before a prestigious security forum, Gates dismissed as dated Cold War rhetoric Russian President Vladimir Putin's charge Saturday that the United States is seeding a new arms race.

A day after Putin blamed U.S. policy for inciting other countries to seek nuclear weapons to defend themselves, Gates responded: "As an old Cold Warrior, one of yesterday's speeches almost filled me with nostalgia for a less complex time. Almost."

Then, as the audience chuckled, he added, however, that he has accepted Putin's invitation to visit Russia.

"We all face many common problems and challenges that must be addressed in partnership with other countries, including Russia," said Gates. "One Cold War was quite enough."

The bulk of his speech was devoted to the future of the NATO alliance, and the need to work together to defend the trans-Atlantic community against any security threats.

He struck a familiar theme — one he pressed during a NATO defense ministers meeting this week, when he urged the allies to follow through on their promises to help secure and rebuild Afghanistan.

"It is vitally important that the success Afghanistan has achieved not be allowed to slip away through neglect or lack of political will or resolve," Gates said. Failure to muster a strong military effort combined with economic development and a counternarcotics plan "would be a mark of shame," he said.

Gates also sketched out the challenges ahead, from Iran's nuclear ambitions and the situation in the Middle East to China's recent anti-satellite tests and Russia's arms sales.

Just eight weeks on the job, Gates used the conference and a NATO gathering earlier in the week to introduce himself to the international community and meet privately with a number of defense ministers.

Delivered amid growing tensions between the U.S. and Russia and to an audience including many Iraq and Afghanistan war skeptics, the speech was the first public test of Gates' diplomatic skills. It came at a venue that at times had been dominated by his more bombastic predecessor, Donald H. Rumsfeld.

So as he neared the end of his remarks, Gates made a deliberate move to separate himself from Rumsfeld and any lingering discord.

In the run-up to the Iraq war, Rumsfeld sharply criticized nations opposed to the conflict — specifically France and Germany — referring to them as "Old Europe."

Without mentioning Rumsfeld's name, Gates said some people have tried to divide the allies into categories — such as east and west, north versus south.

"I'm even told that some have even spoken in terms of 'old' Europe versus 'new,'" Gates said. "All of these characterizations belong in the past."