Prime Minister Stephen Harper said Thursday that the "facts on the ground" convinced him that the Afghan military needs further training.

Harper made the comment in Seoul as he explained his rationale for keeping Canadian troops in Afghanistan beyond the scheduled withdrawal deadline of 2011.

"I don't want to risk the gains that Canadian soldiers have fought for and that they have sacrificed in such significant numbers for by pulling out too early, if we can avoid that," he said after a series of bilateral meetings.

Harper did not offer specifics about numbers of troops.

On Monday, CBC News reported the extension would include up to 1,000 military members to train Afghan soldiers and police officers. The number includes up to 750 trainers and at least 200 support staff.

From left, British Prime Minister David Cameron, Australian Prime Minister Julia Gillard, Canadian Prime Minister Stephen Harper and French Finance Minister Christine Lagarde walk together as they visit the War Memorial of Korea in Seoul on Thursday. ((Darren Staples/Reuters) ) Harper is in Korea to participate in the G20 summit.

Earlier Thursday, he attended a Remembrance Day ceremony at the Korean War Memorial.

British Prime Minister David Cameron, Australian Prime Minister Julia Gillard and French Finance Minister Christine Lagarde were also present at the ceremony, honouring those who died in the Korean War.