An assault weapons ban sought by President Barack Obama as part of his controversial proposed gun safety measures seems to stand little chance of surviving because of expected solid opposition in the US Senate.



Senate Majority Leader Harry Reid decided that it won't be part of the gun control bill, the ban's sponsor, Senator Dianne Feinstein, said on Tuesday.



"I very much regret it," Feinstein told reporters of Reid's decision. "I tried my best."



Less than half of the Senate backs the assault weapons ban, Reid said earlier, which would condemn it to failure when gun control legislation comes to the floor of the chamber next month.



Reid said he wanted to bring the gun bill to the full Senate that would have enough support to overcome any Republican attempts to prevent debate from even starting.



It was the latest blow to the White House's gun control plans which are fading as the Republicans and even some Democrats baulk at taking on the powerful gun lobby.

Prohibition on the sale of assault weapons was always the most controversial element of Obama's attempt to stem gun violence since December's massacre at a Connecticut school where 26 people, mostly children, died.

Right to bear arms

Backed by a lobbying campaign from the National Rifle Association, many legislators argue that bringing back a ban that ran out in 2004 infringes Americans' constitutional right to bear arms.

Other gun control efforts like universal background checks on people buying firearms are also struggling in the Congress, despite public anger at the Connecticut shooting and other massacres.

"There are many things that can be done to reduce gun violence - including restricting high-capacity magazines, strengthening background checks, stopping traffickers and improving school safety." - Senator Carolyn McCarthy



Along with immigration reform, the gun control is a top domestic policy priority for Obama at the start of his second term, and White House Chief of Staff Denis McDonough refused to concede defeat on the assault weapons ban.

Sixty votes would be needed to clear an anticipated Republican procedural roadblock.

The Democrats control the chamber, 55-45, meaning that a number of Reid's fellow Democrats have made it clear that they intend to oppose renewing the ban.

Watered down

The Democrats who support outlawing assault weapons sales appeared resigned.

Representative Carolyn McCarthy of New York said she would be disappointed if Congress refused to renew the prohibition.

"But there are many things that can be done to reduce gun violence - including restricting high-capacity magazines, strengthening background checks, stopping traffickers and improving school safety," McCarthy said.

The ban on assault weapons like the one used in the Connecticut shooting is one of four gun control bills that the Democratic-led Judiciary Committee has sent to the full Senate.

A proposal to provide funding for school security is now the only gun violence measure sure to pass. Two others face an unclear future.

An effort to expand background checks on gun buyers has run into opposition from the Republican legislators who fear that could be a first step toward registering gun owners.

Meanwhile, Colorado state's Democratic governor is expected to sign new restrictions on firearms in the state eight months after dozens of people were shot in a movie theatre.

Governor John Hickenlooper plans to sign new limits on ammunition magazines and a landmark expansion of background checks on Wednesday in his office.