The government does not recognise the Rohingyas as belonging to a national ethnicity, Radio Free Asia quoted Myint Kyaing, director-general of the Department of Population under the Ministry of Immigration, as saying.
However, they can still identify themselves in the census. There is a box for "other" with space for anyone living in Myanmar to write any group or name they wish to be identified as, he said.
His statement came as lawmakers in western Rakhine state, where Rohingyas are reeling from deadly sectarian violence believed perpetrated by ethnic Buddhists, endorsed a proposal to shut down unregistered non-government organisations in the volatile state.
Many NGOs, including Doctors Without Borders (MSF) which was expelled from Rakhine recently, have been trying to help the Rohingyas, who the government considers illegal immigrants from Bangladesh, although many have lived in the country for generations. The UN says they are among the world's most persecuted minorities.
Myint Kyaing was responding to concerns by ethnic Rakhines over social media reports indicating that Rohingyas would be officially recognised in the census.
The census is to be carried out between March 30 and April 10.
"This is not the government’s list — it is from the Muslim group’s [proposed] list," he told the Radio Free Asia Myanmar Service.
"We don’t have any code number [on the census] for the Rohingya ethnicity in our country."
When asked what code number 914 represented on the census, which reports had said was designated for the Rohingyas, Myint Kyaing said it denotes an "other" category of ethnicities not recognised by the government.
"We have code number 914 for 'others' — people who are not included in the [official] 135 ethnic groups of Myanmar. It is used for all others," he said.
The US$75-million census project is being jointly run by the Myanmar government and the UN Population Fund (UNFPA). It will mobilise around 100,000 schoolteachers to count every person in the country for the purpose of national planning and development.
Myint Kyaing said that despite the involvement of the UN, the government would not be pressured to include the Rohingyas on the survey.
"We will only have UNFPA's technical help," he said. "We won't let them be involved in the policy behind the census."
International groups have criticized Myanmar’s 1982 Citizenship Law, which omits Rohingyas from the list of 135 recognised ethnic minorities, as discriminating against the group and effectively barring them from citizenship.
Rohingya activists have argued that many of the 800,000 Rohingyas living in Myanmar should be eligible under Article 6 of the law, which states that anyone who is "already a citizen on the date this law comes into force is a citizen".
Myint Kyaing said that the government was working to prevent protests by ethnic Rakhines over the social media reports.
Ethnic violence in Rakhine state has killed more than 200 people since 2012 and left tens of thousands displaced.
Many have fled to Thailand, only to be rounded up by human traffickers and pressed into work in Malaysia and other countries.