Barack Obama has acknowledged the outpouring of support for stricter gun laws after last Friday's deadly school shooting in Connecticut.
In a new video , the president responds to the "We the People" public petition section on the White House website.
Nearly 200,000 people have urged the Obama administration to address gun control in one petition, and others related to gun violence have amassed more than 400,000 signatures.
"In the days since the heartbreaking tragedy in Newtown, Connecticut, hundreds of thousands of you, from all 50 states, signed petitions asking us to take serious steps to address the epidemic of gun violence in this country," Mr Obama said.
"We hear you," he reassured the petitioners.
"I will do everything in my power as president to advance these efforts because if there's even one thing we can do as a country to protect our children, we have a responsibility to try."
Mr Obama joined a moment's silence on Friday morning at 9.30am ET (2.30pm GMT) marking exactly one week since the shooting that killed 20 children and six adults at the Sandy Hook elementary school.
Churches in Newtown and elsewhere rang their bells once for each of the massacre's victims, and many people paused and stood in driving rain to mark the moment.
The National Rifle Association (NRA), the country's foremost gun lobby, was also planning a news conference on Friday at 11am ET (4pm GMT).
The president has challenged the NRA to "do some self-reflection" and join a broad effort to reduce gun violence.
The organisation said on Tuesday it would offer "meaningful contributions to help make sure this never happens again".
Mr Obama has begun laying the groundwork for a push to tighten gun laws, address mental health needs and re-examine the glamorisation of guns and violence.
Vice President Joe Biden is leading a working group of administration officials and outside advisers to offer recommendations by January.
The group is considering reinstating a ban on military-style assault weapons, which expired in 2004, closing loopholes that allow gun buyers to avoid background checks and restricting high-capacity magazines.
Gun-control measures have faced strong opposition from politicians in Congress for the past decade but Mr Obama has suggested he intends to make it a key part of his agenda next year.