The White House said that the "Hamas" group has chosen war by refusing to release hostages held in the Gaza Strip, Agence France-Presse reported, BTA reports.
Israel launched the most intense strikes on the enclave since January 19, when the Gaza ceasefire agreement came into effect.
"Hamas" could have released the hostages to extend the ceasefire, but refused and chose war," said Brian Hughes, a spokesman for the US National Security Council.
According to data from the "Hamas" Gaza health ministry says more than 400 people have been killed and more than 500 injured in the strikes.
Israeli Prime Minister Benjamin Netanyahu said he ordered the strikes because of the lack of progress in talks to extend the ceasefire.
Officials quoted by the Associated Press said the operation was open-ended and expected to expand.
The White House said it had consulted with Netanyahu and expressed support for Israel's actions.