Addressing the press at the Jomo Kenyatta International Airport (JKIA) on Friday, Health Cabinet Secretary Sicily Kariuki, however said that state health facilities are capable of handling any cases that may arise.
This is the ninth time Ebola has been recorded in the vast, forested central African nation since it was first identified near its northern Ebola river in the 1970s.
"We are very concerned and planning for all scenarios, including the worst case scenario", Peter Salama, WHO's deputy director-general of emergency preparedness and response, said in Geneva on Friday.
The WHO's Regional Director for Africa, Dr Matshidiso Moeti, added: "We know that addressing this outbreak will require a comprehensive and coordinated response".
Cases have already been reported in three separate locations around Bikoro, and Mr Salama warned there was a clear risk the disease could spread to more densely populated areas.
The two Ebola cases were confirmed as the Zaire strain after officials in the capital, Kinshasa, were alerted early this month to the deaths of 17 people from a hemorrhagic fever and traveled to the Bikoro area to perform tests.
The West African outbreak lasted for three years, infected about 28,000 people, killed 11,000 and spread out of Africa to places like the U.S. and Europe.
The Wellcome funding will be made available to the DRC government and the World Health Organization as they seek to contain the outbreak's spread.
The virus spreads through direct contact with bodily fluids from an infected person or even a primate or fruit bat.
Congo's health ministry on Tuesday, May 8, described the fresh outbreak as a "public health emergency with global impact".
Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, told the Washington Post that Ebola outbreaks are unsafe in an increasingly urbanizing Africa because once infections spread to a metropolitan area, they become much more hard to control. Symptoms usually begin with fever, weakness, soreness, and headache, often followed by vomiting, diarrhea, rashes, organ failure, and sometimes internal and external bleeding.
The virus is transmitted to people from wild animals and spreads in the human population through human-to-human transmission.
An Ebola vaccine that worked well in a clinical trial in Guinea held in 2015, has yet to be approved by regulatory authorities but could be used under emergency protocols.