LISBON, Portugal - Stephen Harper kicks off the NATO summit today with a meeting with Secretary General Anders Fogh Rasmussen.

The prime minister is holding a bilateral meeting with the NATO chief before Friday's formal of opening of the two-day gathering of the alliance's 28 leaders and 20 other invitees in Lisbon, Portugal.

Rasmussen has already thanked Canada for its decision to deploy 950 military trainers to assist Afghanistan's security forces to 2014 -- the date the NATO-led security mission has set to be withdrawing western troops from the war-torn country.

Rasmussen told Portuguese television that NATO has made mistakes in Afghanistan by not providing enough military resources, but was optimistic about the alliance's 2014 transition plan to be unveiled here.

The Canadian commitment coincides with NATO's broader plans for eventually scaling back western military forces and turning the security of the country over to the Afghan security forces.

Afghan President Hamid Karzai is to give a heavily anticipated address to the summit on Saturday in which he'll outline his country's plans for co-operating with the handover.

Karzai arrives in Lisbon after public spat this past week with the U.S. general who leads coalition forces in Afghanistan.