The idea was floated late last year by former defence minister Rob Nicholson as the Harper government agreed to expand military co-operation with President Petro Poroshenko's government.
Jason Kenney, the current defence minister, has said Canada would be interested in joining a U.S.-led training mission, which would include instructing combat forces.
However, the military police plan to provide classroom instruction, possibly this summer, was more advanced and separate from what Kenney was suggesting.
National Defence proposed to run two types of courses of one to two weeks duration each, taught by up to four members of the Canadian Forces.
A defence spokesman, Dan Lebouthillier, says a preparatory meeting slated for next month has been postponed because Ukrainian leaders were unavailable.
"This could delay the running of the first military police course due to the lead times required to co-ordinate participation of the Ukrainian armed forces," he said in an email.
Using military cops to instruct their Ukrainian counterparts was billed by the Conservatives as another clear demonstration of Canada's support of Ukraine in the face of Russian-backed rebel factions.
How long the delay will last is unclear, especially in light of the shaky ceasefire, which was rattled by the deaths of three Ukrainian soldiers on Friday.
Under the terms of the Minsk II peace deal recently struck by Ukraine, Russia, France, and Germany, all armed foreign forces were to be pulled out the country. The clause was aimed at the Russians, but some international commentators in eastern Europe have suggested it could just as easily apply to western troops.
Lebouthillier says military police trainers would be on safe legal ground.
"The courses we are proposing for the Ukrainian military police are similar to the types of professional development courses we have been providing to Ukraine as part of the military training and co-operation program," he said.
"The courses will be provided by unarmed members of the Canadian Armed Forces in a classroom setting."