An investigation into possible sabotage of the Nord Stream gas pipeline comes as work complicates World War II-era munitions at the bottom of the Baltic Sea.
Danish Defense Minister Morten Bodskov told journalists on the sidelines of the NATO meeting, AFP writes.
"This is a zone marked by the presence of ammunition - used or not - from the Second World War," Bodskov told reporters.
"There are many things at the bottom of the sea, so it is not so easy. But the work continues and is going well," he added.
The strings of the Nord Stream gas pipeline were damaged by four explosions at the bottom of the Baltic Sea in late September, leading to large gas leaks.
Sweden announced that previous underwater inspections had confirmed suspicions of possible sabotage.
"Together with Sweden and Germany, Denmark is conducting a successful investigation that is progressing. What we discover will, of course, be made public," the minister said.
Russia was denied access to the investigation into the sabotage in which it is suspected.
Russia has stated that it will not recognize the outcome of the investigation into the Nord Streams without its participation.