Russian President Vladimir Putin , left, and US-Secretary of Defense Robert Gates sit side by side during the Security Conference in Munich, southern Germany, Saturday, Feb. 10, 2007. Global conflicts are on the agenda of the 3-day-conference. [AP]

MUNICH, Germany - Pentagon chief Robert Gates responded Sunday to Vladimir Putin's assault on US foreign policy by saying "one Cold War is enough" and that he would go to Moscow to try to reduce tensions. Gates also sought more allied help in Afghanistan.

He delivered his first speech as Pentagon chief at a security conference in Germany and then flew to Pakistan to discuss fears of a renewed spring offensive by Taliban fighters in neighboring Afghanistan.

US policy creating new arms race - Putin Russian President Vladimir Putin warned Saturday that the United States' increased use of military force is creating a new arms race, with smaller nations turning toward developing nuclear weapons.

Pakistan, a close US ally in the fight against terrorism, has faced charges that the Taliban militia stage attacks from Pakistan against Afghan government troops and NATO- and US-led coalition troops.

Gates' rebuke of the Russian president relied on humor and some pointed jabs.

"As an old Cold Warrior, one of yesterday's speeches almost filled me with nostalgia for a less complex time. Almost," Gates said. Then, as the audience chuckled, the defense secretary said 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."

In his speech Saturday, Putin blamed US foreign policy for inciting other countries to seek nuclear weapons to defend themselves from an "almost uncontained use of military force."

The Russian leader said "unilateral, illegitimate actions have not solved a single problem, they have become a hotbed of further conflicts" and that "one state, the United States, has overstepped its national borders in every way."

Gates also made an urgent call for NATO allies to live up to their promises to supply military and economic aid for 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 said that prisoner abuse scandals in Iraq and Guantanamo Bay, Cuba, and other mistakes have damaged America's reputation. It will take work, he said, to prove that the US still is a force for good in the world.

While he did not mention the war in Iraq, Gates told officials at the security conference that Washington must do a better job of explaining its policies and actions.

For the past century, he said, most people believed that "while we might from time to time do something stupid, that we were a force for good in the world."

Many continue to believe that, Gates said. But, he added, "I think we also have made some mistakes and have not presented our case as well as we might in many instances. I think we have to work on that."

The bulk of his speech was devoted to the future of the NATO alliance and the need to work together to defend against threats.

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 this past week to debut on the international stage and meet privately with some of his counterparts.

In other comments, he said the Bush administration would like to close the Guantanamo Bay detention facility, but there are some terrorists there who should never be let free. Gates also said detainee trials there will be conducted in the open and with adequate defense for the prisoners.

The first public test of Gates' diplomatic skills came at a venue that at times was dominated by his more bombastic Pentagon predecessor, Donald H. Rumsfeld.

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

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

Without mentioning Rumsfeld's name, Gates said some people have tried to divide the allies along lines such as East and West, North and 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."

In Pakistan, Gates planned talks with the president, Gen. Pervez Musharraf and other top officials on cooperation in counterterrorism and efforts by Pakistan to stop militants from moving across the border with Afghanistan, a senior Pakistani government official said Sunday. The official spoke on condition of anonymity because he did not have the authority to speak formally about Gates' visit.

Pakistan denies the charges that the Taliban are staging attacks from inside Pakistan and says it has deployed some 80,000 troops along its rugged border with Afghanistan to track down militants.

Pakistan's border regions along Afghanistan long have been suspected to be the hiding places for al-Qaida leader Osama bin Laden and his deputy, Ayman al-Zawahri.

American forces in eastern Afghanistan have launched artillery rounds into Pakistan to strike Taliban fighters who attack remote US outposts, the commander of US forces in the region told The Associated Press on Sunday.

Musharraf acknowledged recently that his outgunned Pakistani frontier guards have allowed insurgents to cross the border and said the army soon would fence parts of the border to stem the problem.

The Pentagon has plans to extend its recent buildup of several thousand combat troops in Afghanistan, initially announced as lasting until late spring, well into next year, a senior US military official said last week.

That move would keep US troop levels at between 26,000 and 27,000 until at least the spring of 2008.