Kfor, which at its height numbered 55,000, was initially deployed a decade ago after Nato's bombing campaign to drive out Serb forces.
Some of the soldiers, who have served in Kosovo since 1999, could be transferred to Afghanistan, where Nato is fighting the Taliban under a US-led coalition.
Fears of violence
Fatmir Sejdiu, Kosovo's president, told Rasmussen he hopes his own troops could join in Nato peacekeeping operations abroad.
Sejdiu says he and Hashim Thaci, Kosovo's prime minister, offered Rasmussen "the presence of Kosovo men in important peacekeeping and stabilisation operations".
Rasmussen, who met with political leaders and the Kfor commander during his one-day visit, said Kosovo was a "high priority" for Nato.
"We will stay committed to ensuring the security in Kosovo and in parallel with that I can confirm that we will continue to assist the Kosovo authorities in the continued development of the Kosovo Security Force," he said.
The lightly armed Kosovo Security Force, formed in January this year, will eventually number 2,500 members in a civilian protection force meant to help in emergency situations.
Its formation was met with anger by Serbia's government and Serbs in Kosovo who fear it will be dominated by ethnic Albanians they do not trust.
There have been fears that Kosovo, which self-declared independence in January 2008, could still see an increase in tensions and violence between its ethnic-Albanian majority and Serb minority.
Kosovo's independence is recognised by 60 countries including the US and most European Union members.
Serbia and Russia, a permanent UN Security Council member with veto rights, have said they will not recognise an independent Kosovo.