The Statue of Liberty will close for a year at the end of October as it undergoes a $27.25m (£16.8m) renovation that will make the interior safer and more accessible, US interior secretary Ken Salazar said.

The renovations are limited to the monument, and Liberty Island will remain open and the statue itself will be mostly unobstructed from view, officials said.

Tegan Firth, a spokeswoman for Statue Cruises, which on an average Saturday during the summer ferries about 18,000 people to Liberty Island, said the renovation will not have a significant impact on visit numbers.

"The entire experience of visiting these national landmarks of the United States remains absolutely the same," she said.

The National Parks Service, which manages the Statue of Liberty National Monument and Ellis Island, said it will close the monument on 28 October after the 125th anniversary of its dedication.

It will be closed the following day, and workers from Joseph Construction, a New Jersey company, will install improved stairways and upgrade electrical and fire suppression systems, elevators and bathrooms.

The National Parks Service said in August 2010 that it would close the statue's crown to upgrade the stairwells and improve safety at Lady Liberty. One reason for it was that the newest fire codes mandate escape routes that would allow the statue to be evacuated within two hours, not possible on the current staircases on either side of the pedestal.

The statue was closed after the 11 September terror attacks for security precautions, but the base reopened in 2004 after a $20m security upgrade. The observation deck at the top of the crown was reopened on 4 July 2009.

The National Parks Service controls the number of visitors to the crown, saying around 240 people visit each day. About 3.5 million people visit the monument every year.

The statue was built in the 1880s, and was a gift from France.