OTTAWA – The U.S. ambassador says deeper co-operation between Canada and the United States on cross-border law enforcement is being held up by the thorny question of whose legal system would deal with a police officer accused of breaking the law.

The ongoing efforts to iron out issues of officer accountability explain the one-year delay in launching two pilot projects for the so-called “next generation” policing program.

The initiative would see Canadian and U.S. officials build on joint border-policing efforts by creating integrated teams in areas such as intelligence and criminal investigations.

But David Jacobson, the U.S. ambassador to Canada, says it has proven to be one of the most challenging elements of the perimeter security pact between the two countries.

For instance, Jacobson asks, if an RCMP officer working in North Dakota shoots somebody, which laws govern the appropriate use of force — those of Canada or the U.S.?

The perimeter security deal aims to ensure the safe, speedy passage of goods and people across the 49th parallel while bolstering defences along the continental border.