The Obama-Hu exchange seemed to go well, while dinner Wednesday night gave Obama and Germany's Merkel a chance to reach greater détente.
The US pledged $900 million, but said the money would not go to Hamas.
Project Moses aims to construct giant steel gates across inlets through which the Adriatic flows into Venice's lagoon.
Concerns about Islamist threat have influenced traditionally pro-Arab Europe's view of the Israeli-Palestinian conflict.
Fueled by the recession, the groups have won members and seats in recent elections.
Italian Prime Minister Silvio Berlusconi (r.) and his foreign minister, Franco Frattini, spoke to the media Wednesday at an EU environmental conference in Brussels.