Reuters reported that the White House announced gun control measures on Monday, compelling more gun venders to acquire licenses, and for gun buyers to go through background checks. The newly implemented measures are within the president’s jurisdiction and require no congressional approval.

“These are not only recommendations that are well within my legal authority and the executive branch, but they’re also ones that the overwhelming majority of the American people, including gun owners, support,” Obama said during a meeting with Attorney General Loretta Lynch and other advisers.

Frustrated by Congress’ inaction on gun control, President Obama had asked his advisers to examine new ways he could use his executive authority to tighten the belt on gun ownership rules, without referring to congress, after multiple mass shootings enraged Americans nationwide.

The White House previously drafted a proposal on gun licenses, but was concerned it could be challenged in court and difficult to enforce. Guns are rather a touchy subject in American politics.

However, Obama is considered to be playing around with fire after bypassing Congress on the subject, which could lead to legal challenges. Republicans now believe that Obama is misusing his authority.

“The president is at minimum subverting the legislative branch, and potentially overturning its will,” Republican Speaker of the House of Representatives Paul Ryan said in a statement before the White House announcement.

Nevertheless, Obama launched his final year with use of executive action which is a move that Republicans define as misuse of power. Congress, which is majority Republican, rejected Obama’s proposals for legislation to tighten gun rules in 2013.

Ultimately, the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives now requires gun sellers at stores, gun shows, or over the internet to be officially silenced and to carry out checks. Obama explained that despite that the measures might not stop all violence and crime, they expected to reduce them significantly.