Thousands of pro-Israel supporters are gathering in the nation's capital this week for the annual American-Israel Public Affairs Committee conference.

Democrat and Republican leaders from all states are discussing Israel's future. Talks center on expanding the U.S.-Israel partnership, as well as Iran's growing nuclear threat.

Vice President Joe Biden said no president has done more to secure the state of Israel than President Obama.

"That's why from the moment the president took office he has acted swiftly and decisively to make clear to the whole world and to Israel that even as circumstances have changed, one thing has not: our deep committment to the security of the state of Israel," Biden said. "That has not changed."

AIPAC is the largest annual gathering of the pro-Israel movement.