WASHINGTON – President Barack Obama endorsed controversial bans on assault weapons and high-capacity ammunition magazines on Monday, as well as stricter background checks for gun buyers – but conceded he may not win approval of all in a Congress reluctant to tighten restrictions.

"Will all of them get through this Congress? I don't know," said Obama. He said lawmakers would have to "examine their own conscience" as they tackle gun control legislation after the horrifying Connecticut school shootings but in the face of opposition from the National Rifle Association and other pro-gun rights groups.

Obama spoke at a midday White House news conference one month after the Newtown elementary school rampage, which ignited a national discussion on preventing mass shootings.