Opposition party leaders released tear gas inside Kosovo's parliament on Wednesday in an attempt to block a vote.

The Self-Determination Movement party released three tear gas canisters in the parliament hall right as the politicians were to start voting on a border demarcation agreement with Montenegro, The Independent reported.

More than 100 parliament members were forced to leave the hall.

The opposition party claims the deal would cause Kosovo to lose 20,000 acres of territory to Montenegro, though that figure is being disputed by experts.

U.S. Ambassador to Kosovo Greg Delawie condemned the use of "violence" on Wednesday, urging lawmakers to return and finish the vote.

Kosovo declared independence from Serbia in 2008 but is not recognized by Belgrade.

Lawmakers hope to qualify for membership into the European Union, and the proposed land deal is required by the EU to give citizens the ability to travel freely between Kosovo and Montenegro, the Independent reported.