(Video: Camilla Schick)
US National Security Adviser Susan Rice toured the Palmahim Air Force base in central Israel on Friday, pledging sustained commitment to Israel's security.
Rice said US and Israel's security cooperation has reached "unprecedented levels' under US President Barack Obama's administration, making great progress in missile defense technology.
"There can be no doubt, whatsoever, America's commitment to Israel's security is unwavering and iron-clad," she said.
Two months ago, US and Israel signed an agreement under which nearly $500 million will be invested in Israel's Iron Dome missile defense system, Rice said.
She said joint research, investment and training will continue.
Budget-strapped Israel is pressing the United States to conclude a deal extending defense aid beyond 2017, when Washington's current $3 billion annual payouts to its Middle East ally expire, officials said on Friday.
The previous Republican administration signed a 10-year deal with Israel in 2007 granting it $30 billion, most of it going on American defense products.
Obama, a democrat, has sparred with Netanyahu over Iran's nuclear program and peacemaking with the Palestinians. But support for Israel's security remains strong in Washington - even as policymakers there slash spending on a range of US military programs.
"Our two nations are forever bound by our shared history and our shared values. And every American dollar spent on Israel's security is an investment in protecting the many interests that our nations share, whether that's preventing rockets from terrorizing the Israeli people, defending against a growing ballistic missile threat in the region, or advancing our commitment to defend freedom and democracy." Rice said.
Rice met Netanyahu and President Shimon Peres on Wednesday in Jerusalem, and with Palestinian Authority President Mahmoud Abbas in Ramallah on Thursday.
Rice's visit, the first in her role as national security adviser, comes as peace talks between Israel and the Palestinians have collapsed. The Obama administration made clear that Rice's trip is part of regularly scheduled talks and that the suspended Middle East peace discussions are not on the agenda.
However, the White House said negotiations with Iran over its nuclear program would be on the agenda in Rice's talks, among other topics. Iran denies that its goal is to build a nuclear weapon.
The US delegation led by Rice in the Israel visit includes representatives from the departments of State, Defense, Treasury and the intelligence community, the White House said.