Obama said he was "deeply concerned" about the loss of life in Gaza and also reiterated the US view that Israel had a right to defend itself from Palestinian rocket attacks.

"It will be the policy of my administration to actively and aggressively seek a lasting peace between Israel and the Palestinians, as well as Israel and its Arab neighbours," Obama said.

"Now we must extend a hand of opportunity to those who seek peace. As part of a lasting ceasefire, Gaza's border crossings should be open to allow the flow of aid and commerce," Obama said.