WASHINGTON (REUTERS) - President Barack Obama is getting updates on the outbreak of the deadly Ebola virus in Guinea, Liberia, Sierra Leone and Nigeria, an administration official said on Monday, noting US agencies had increased their assistance in the past several weeks.

The outbreak of the highly infectious disease has killed 672 people.

The United States has been providing supplies, including personal protective equipment, the administration official said.

"We have been engaged on this outbreak since April, when the first cases were reported and have increased response significantly over the last several weeks as the outbreak deepened," the official said.

Ms Susan Rice, Mr Obama's national security adviser, said in a televised interview on Monday that the outbreak was of "grave concern".

"We are very much present and active in trying to help the countries of the region and the international authorities like the World Health Organisation address and contain this threat. But it is indeed a very worrying epidemic," Ms Rice told MSNBC.