Team Rubicon, a volunteer group of military veterans and first responders, is sending a 15-member team from California to the Philippines to help victims. It was working with the State Department and also coordinating cell-phone donations, Kerry said today.
Incident commander for Team Rubicon Vince Moffitt said they're focusing on the hard hit city of Tacloban.
"I think it's going to be one of the biggest, most tragic events we've witnessed so far," Moffitt told ABC News Radio, adding that initial reports indicated "this is going to be a massive, massive destruction. Unfortunately, it looks like a lot of loss of lives. Complete catastrophic events."
Annette Lynn of Save the Children told the BBC they're working as quickly as possible to help the homeless.
"Quite a dire situation at the moment. ...They have no home, they have no assets and they have nothing on them at all. They need food, they need clean water, they need electricity," she said.
Meanwhile, the typhoon made landfall in northern Vietnam today after crossing the South China Sea. Authorities there evacuated hundreds of thousands of people, but there were no reports of significant damage or injuries.
It was downgraded to a tropical storm as it entered southern China later today, but weather officials forecast torrential rain in the coming 24 hours across southern China.
ABC News Radio and the Associated Press contributed to this report.