The Bush administration said a rocket attack in Gaza on Tuesday was a justified response to rocket attacks on Israel.
The Israeli barrage hit two offices of the Aksa Martyrs' Brigades and a bridge the army said was used by terrorists to reach areas where they fire rockets.
At the State Department, spokesman Adam Ereli said Israel's rockets were in response to attacks on its territory.
"What we would like to see is effective measures against such acts so that the measures Israel is taking are not necessary," Ereli said.
In that vein, the spokesman said Maj. Gen. Keith Dayton, the new US security specialist for the region, had arrived in the area for talks with Israeli and Palestinian Authority officials.
Speaking of Israel's rocket barrage, Ereli said: "We see it in the context of failure to address the security situation" by the Palestinians.