UNHCR spokeswoman Melissa Fleming said the agency was reviewing its guidelines on refugees from the two countries when Australia made its announcement.
Fleming pointed out that the situation in Sri Lanka was changing.
"We are currently examining that (Australian) announcement... particularly with regards to issues around detention of vulnerable persons and the provision of social support for the asylum seekers who are subject to this suspension," she said.
"This decision from the Australian government is taken independently from us. We are looking at the implications," she added.
Australian Immigration Minister Chris Evans said earlier that the government would temporarily suspend processing new visa applications from asylum seekers from Sri Lanka and Afghanistan, "in the light of the changing circumstances" in those countries.
Fleming noted that the UNHCR is "in a process ourselves of looking at the situation in Sri Lanka and Afghanistan and will be issuing those guidelines."In Sri Lanka's case, current guidelines were made based on "the situation of generalised violence there -- basically that no Tamil should be returned forcibly, and that they should be considered individually, under the 1951 (refugee) convention," she said.
"This situation in Sri Lanka is changing... many of the internally displaced persons have now been able to return to their homes. There is freedom of movement... in this case, we are reexamining our guidelines," the UNHCR spokeswoman added.
Fleming conceded however that events in Afghanistan were "incredibly more complex." She nonetheless declined to comment on Australia's move, stressing that the agency was "not making a judgement on that at this point."