The authorities hope to evacuate a total of around 2.5 million people, but could not say on Monday whether they would have time before Sitrang reaches all threatened areas.
Among those who have not been able to be relocated are 33,000 Rohingya who have fled to Bangladesh and are living cramped on an island threatened by Sitrang.
At least five people have died as the cyclone made landfall in the eastern parts of the country, and more deaths are feared as it moves west.
Even in the capital Dhaka, several hundred kilometers from the storm, trees have fallen and roads have been flooded.
In more coastal areas, tides are feared to reach levels more than three meters higher than normal, threatening millions of homes.
Sitrang is also expected to reach India during Tuesday.