Russia is once again retaliating against sanctions imposed by Canada over the ongoing crisis in Ukraine.

The Russian Foreign Ministry has not said how it will retaliate, but the Reuters news agency says the country will be expanding its list of Canadian officials barred from the country.

This latest round in the diplomatic tit-for-tat comes just a few days after Prime Minister Stephen Harper announced sanctions against 16 additional Russian banks, companies, and other entities. Harper said the move was made to protest Russia's "illegal occupation" of Ukraine.

"The measures we are announcing today will continue to increase economic pressure on Russia and those responsible for the crisis in Ukraine,” he said in a statement.

Over the past several months, Canada has issued a series of sanctions against Russian nationals and companies. In response, Russia has imposed its own sanctions and bans against several Canadian officials and lawmakers.

Russian leader Vladimir Putin told diplomats Wednesday that the country has pulled back its troops from the Ukrainian border, but the U.S. military said it had seen no sign of a Russian troop pullback.