* Hieroglyphics worn away on 3,500-year-old monument
* Obelisk has stood near museum in Central Park since 1881
By Kristina Cooke
NEW YORK, Jan 7 (Reuters) - The Egyptian government official charged with protecting his country's ancient monuments is threatening to take back an iconic obelisk in Central Park unless New York City takes steps to restore it.
The stone obelisk "has been severely weathered over the past century" with no effort made to conserve it, Zahi Hawass, secretary general for Egypt's Supreme Council of Antiquities, wrote in a letter this week to New York Mayor Michael Bloomberg.
The obelisk, which commemorates King Thutmose III, has stood behind the Metropolitan Museum of Art since 1881. At 71 feet (21.6 metres) tall, it is known as "Cleopatra's Needle" and is one of a pair. The other is in London.
The obelisk dates back roughly 3,500 years and was given to the United States in the 19th century by an official in Egypt.
"I have a duty to protect all Egyptian monuments whether they are inside or outside of Egypt," Hawass wrote in the letter.
"If the Central Park Conservancy and the City of New York cannot properly care for this obelisk, I will take the necessary steps to bring this precious artifact home and save it from ruin," he wrote.
The hieroglyphics have completely worn away in places, he said.
Jonathan Kuhn, director of art and antiquities for New York's Parks Department, told local news website DNAinfo that there was no evidence of "any significant ongoing erosion."
A Metropolitan Museum study in the 1980s found the granite was "largely inert" and that damage to the inscriptions and the base of the monument occurred in the distant past, Kuhn said.
"We have been working in recent years with the Metropolitan Museum and the Central Park Conservancy to further analyze the condition of the obelisk and monitor its condition," Kuhn told DNAinfo.
Representatives of the mayor declined to comment.
Editing by Daniel Trotta and Will Dunham