Anders Fogh Rasmussen took the helm of NATO on Monday with a pledge to prevent Afghanistan from once more becoming the hub of international terrorism and to build a new strategic partnership with Russia.
On his first day in office, the former Danish prime minister laid out his priorities at a time when NATO is embroiled in its biggest ever mission and ties with Moscow are only just beginning to recover after last year's war in Georgia.
Around 100,000 foreign troops are currently stationed in Afghanistan to counter an insurgency by the Taliban against the government of President Hamid Karzai.
The new secretary-general told reporters that troops serving in NATO's mission would help prevent Afghanistan from "becoming again a grand central station of international terrorism."
Rasmussen took over a day after US Defence Secretary Robert Gates flew to Belgium for a secret meeting with the top US commander in Afghanistan, amid speculation the general may be seeking more American forces for the war.
The Defence Department said Gates met General Stanley McChrystal at a US air base in Belgium for a progress report on an assessment of the Afghan war being prepared by the commander and due later this month.
The Taliban have stepped up attacks in the countdown to national elections on August 20, their latest bombing killing 12 people on Monday in the western city of Herat.
Seventy-five foreign soldiers were killed last month according to the independent www.icasualties.org website, making July the deadliest month for troops since the US-led invasion in late 2001.
Rasmussen, who has a four-year term in office, said that the long-term goal was to "move forward concretely and visibly with transferring lead security responsibility in Afghanistan to the Afghans."
He added: "I believe during my term Afghans must take over lead responsibility for security in most of their country."
In a weekend newspaper interview, the 56-year-old also said that he would support dialogue with moderates within the Taliban.
The Islamist militia had ruled Afghanistan until late 2001 but was toppled by US-led forces after it refused to hand over Al-Qaeda leader Osama bin Laden in the wake of the September 11 attacks in New York and Washington.
The foreign ministers of France and Britain have recently argued that it is time to engage with Taliban willing to renounce violence.
The new secretary-general, who succeeds Dutch diplomat Jaap de Hoop Scheffer, also wants to defrost relations with Russia.
Ties between Moscow and the alliance plummeted last August when Russia and NATO hopeful Georgia briefly went to war, although the two sides agreed in June to resume political and military cooperation.
Rasmussen said while disagreements remained with Russia, they should not be allowed to poison ties and there were many areas of common interest.
"I believe that during my term, we should develop a true strategic partnership. We should enhance practical cooperation in areas where we share security interests," he added, citing Afghanistan, counter-terrorism, piracy, and nuclear non-proliferation.
He said he regarded it as "a very important challenge to convince the Russian people and the Russian political leadership that NATO is really not an enemy of Russia, that NATO is not directed against Russia."
Rasmussen said the war in Georgia had had "a very negative impact" and that "real differences" remained.
"But we cannot let our areas of dispute poison the whole relationship," he added.
Rasmussen said he had asked former US Secretary of State Madeleine Albright to head a committee of experts to work out a "new strategic concept" for NATO.
"They will consult as widely as possible, in NATO and far beyond: governments, think-tanks, NGOs and other international organisations," he said. "They will then submit their conclusions to me."
Afghanistan: Training Ground for War on Russia