U.S. Defense Secretary Ash Carter has welcomed Denmark's decision to expand its military campaign against Islamic State militants to include airstrikes in Syria.
Denmark has been a part of the U.S.-led coalition bombing Islamic State targets, but had done so only in Iraq.
The country's parliament voted Tuesday to approve operations in Syria. The total Danish contribution to the coalition will include seven F-16 warplanes and 400 military personnel, some 60 of them special forces.
Carter said the move shows "growing momentum" in the fight to defeat Islamic State and will increase military pressure on the group.
The U.S. launched the first airstrikes against the militants in Iraq in August 2014, shortly after they had seized control in large portions of the northern and western part of the country. The coalition effort expanded to Syria a month later.
Denmark joins Australia, Canada, France, Jordan, the Netherlands and Britain among countries conducting airstrikes in both Iraq and Syria. To date, the coalition has carried out more than 11,500 strikes.