The Northern Territory's Health Department has declared a "code yellow" at Royal Darwin and Palmerston hospitals due to a peak in demand over the past week.

NT Health said it had enacted the code yellow after "a steady increase of patient admissions".

Code yellow declarations allow hospitals to take certain steps to ease strain on the system, including discharging patients earlier than normal and the cancelling of some surgeries.

An email from NT Health sent to staff said the hospitals were "experiencing significant levels of demand and high occupancy".

"A code yellow has been enacted to allow us to manage the situation and implement enhanced measures to ease pressures and improve patient flow," the email said.

In a statement, NT Health said elective surgeries had not been deferred and that surge-management plans were now in place.

"Patient safety is a priority, and we thank our dedicated staff at Royal Darwin and Palmerston hospitals for their hard work during these periods of high demand, to ensure Territorians continue to receive the best patient-centred care possible," NT Health said in its statement.

Australian Salaried Medical Officers Federation NT branch president Dr Thomas Fowles said the code yellow was "the health service crying out for help from the government".

"We need more beds, more nurses, more doctors," he said.

"It's clear that the cost of providing care in the Northern Territory outweighs what the federal government provides.

"Canberra needs to stop neglecting the health of Territorians."