"In order to succeed, we must help Afghanistan become sufficiently solid in order to withstand the insurgency. Because that is the only way to fight against terrorism."
But two Nato members said on Friday they will not send more troops to Afghanistan unless its presidential runoff next month creates a legitimate government.
Eimert Van Middelkoop, the Dutch defence minister, said his country is awaiting the final election results "because the legitimacy of the Afghan government is key", as well as a decision by Barack Obama, the US president, on his strategy in Afghanistan.
Soeren Gade, Danish defence minister, said allies will not increase troop levels until they are assured the new government in Kabul is committed to the Nato goals.
An official told the Associated Press news agency that McChrystal would not push Nato members to adopt his recommendations at Friday's meetings, saying that he was expected to outline his vision of the war in Afghanistan.
A document seen by the news agency affirm Nato's intention to begin a gradual transition of power to Afghan forces, but did not provide a deadline for such a move.
"[This] will entail a change in the nature of the security assistance provided to the Afghans and the balance of responsibility," the document said.
Nato's Afghan mission currently involves 65,000 US troops and 39,000 from allied nations.