Some 1,000 Europeans in Nepal are unaccounted for, according to a European Union official.
The EU's Ambassador to Nepal Rensje Teerink told reporters that "of course doesn't mean they are dead. It just means they haven't reported back".
Most of the people not accounted for were tourists and trekkers and it's near impossible to keep track because most do not register with their embassies.
More than 6,200 deaths have been caused by the earthquake which struck on April 25.
Meanwhile, the UN humanitarian chief, Valerie Amos told reporters at the UN compound in Nepal's capital that aid workers face "immense logistical challenges" trying to get aid to mountainside villages where helicopters couldn't land and where some roads were destroyed.
"Of course we are worried that it is taking so long to get to people who desperately need aid. Some of those villages are virtually flattened. But it's very, very hard to see how we're going to get to them," she said.
Nepalese leaders and outsiders were working to get aid to those in need. But the scale of the devastation, she said, would challenge any government.
The UN humanitarian office says more than 130,000 houses were reported destroyed.
The World Health Organization says a quick assessment of Nepal's worst-hit districts has found some hospitals damaged or destroyed but most are coping well with no extra staff or beds required. However, they are in need of essential medicines, equipment and materials.
The WHO says the Nepalese health system took measures to prepare for such emergencies.
The agency says it is focused on preventing the possible spread of diarrhoeal diseases among at least 2.8 million displaced people, especially those living in 16 makeshift camps in Kathmandu. So far, the number of cases has not exceeded expectations and no camps have reported an increase in disease or any outbreaks.