Obama, flanked by bill sponsors Sen. Barbara Boxer, D-Calif., and Rep. Howard Berman, D-Calif., and Jewish leaders signed the United States-Israel Enhanced Security Cooperation Act of 2012 in an Oval Office ceremony.
Obama said the U.S. commitment to Israel is unshakable.
"In many ways what this legislation does is bring together all of the outstanding cooperation that we have seen really at an unprecedented level between our two countries," Obama said, adding, "We are standing by our friends in Israel when it comes to [terrorist] of attacks."
The United States plans to commit $70 million more to the Iron Dome anti-missile system, Obama said. Southern Israel comes under regular rocket fire from Gaza.
Obama also talked about the recent suicide bombing in Bulgaria targeting Israeli tourists.
"Let me just close by saying that the tragic events that we saw in Bulgaria emphasize the degree to which this continues to be a challenge not just for Israel, but for the entire world -- preventing terrorist attacks and making sure the people of Israel are not targeted," Obama said.
The president has pledged to visit Israel if he is re-elected. U.S. Secretary of State Hillary Clinton, top administration anti-terrorism adviser John Brennan and national security adviser Tom Donilon have visited Israel in recent weeks. Secretary of Defense Leon Panetta is scheduled to arrive next week "to further consult and find additional ways that we can ensure such cooperation," the president said.