Speaking after a high-level meeting of flu experts and US security officials in Geneva, a WHO official said an deal had been reached in principle to keep details of the controversial work secret until deeper risk analyses could be carried out.
"There is a preference from a public health perspective for full disclosure of the information in these two studies. However there are significant public concerns surrounding this research that should first be addressed," said Keiji Fukuda, the WHO's assistant director-general for health security and environment.
The WHO called the meeting to break a deadlock between scientists who have studied the mutations needed to make H5N1 bird flu transmit between mammals, and the US National Science Advisory Board for Biosecurity (NSABB), which wanted the work censored before it was published in scientific journals.
Biosecurity experts fear mutated forms of the virus that research teams in The Netherlands and the United States independently created could escape or fall into the wrong hands and be used to spark a pandemic worse than the 1918-19 outbreak of Spanish flu that killed up to 40 million people.
WHO spokesman Gregory Hartl said that because of these fears, "there must be a much fuller discussion of risk and benefits of research in this area and risks of virus itself."
The H5N1 virus, first detected in Hong Kong in 1997, is entrenched among poultry in many countries, mainly in Asia, but so far remains in a form that is hard for humans to catch.
It is known to have infected nearly 600 people worldwide since 2003, killing half of them, a far higher death rate than the H1N1 swine flu which caused a flu pandemic in 2009/2010.