US President's gun control options each have legal pitfalls

President Barack Obama is expected to announce new gun control curbs this week, but he will have to decide whether to take bold action that would likely spark a major legal challenge from opponents or a more cautious route that may be less effective, legal experts said.

Obama, who has expressed deep frustration about U.S. gun control regulations after a series of mass shootings at schools and other places during his presidency, said he will meet U.S. Attorney General Loretta Lynch on Monday to discuss gun control measures that do not require congressional approval.

The president said in his weekly radio address on Friday he has received "too many letters from parents, and teachers, and kids, to sit around and do nothing" about the issue.

The Washington Post and Politico reported late last week that one of Obama's main proposals would require some unlicensed gun dealers to get licenses and conduct background checks on potential buyers. Current law exempts smaller dealers who often operate at gun shows and sell online.

It would also almost certainly prompt lawsuits by gun advocates claiming the president lacks the authority to change the legal definition of who must obtain a dealer's license.

The conservative advocacy group Freedom Watch plans to sue to block any executive order on gun control, Larry Klayman, the group's general counsel, told Reuters on Sunday.

An executive order would draw immediate comparisons to Obama's initiative aimed at protecting five million undocumented immigrants from deportation. Challengers sued and won an injunction that blocked the move. The administration has asked the U.S. Supreme Court to take up that case.