WASHINGTON - The United States has sent FBI teams to help Belgian authorities investigate the recent attacks that killed 35 people, including several US citizens, and senior US and Belgian officials will discuss the cooperation this week, the White House said on Thursday."Belgium has accepted our assistance. We have FBI teams on the ground assisting with the investigation. We are sharing information and intelligence with Belgium as it relates to terrorist threats," White House deputy national security adviser Ben Rhodes told a news briefing.Rhodes said the Belgian interior minister was expected to discuss the security cooperation with Attorney General Loretta Lynch during the Nuclear Security Summit in Washington this week."We do believe that Belgium is taking this very seriously and we have had effective coordination in supporting their investigation and trying to disrupt additional plots," Rhodes said.