The Hong Kong Commercial Daily said the carrier’s maiden voyage has been put off for a month due to mechanical problems.
"As this is our first aircraft carrier, it's not abnormal that the vessel encounters certain problems. That's why we have never formally announced any timetable for its trial navigation," an unidentified Chinese military official told the paper. He added that the problems the vessel were not serious and will not affect future operations.
"We have exercised extreme caution in dealing with technical details as we want the ship to make its debut in the best possible shape. We don't want it to go wrong on its maiden cruise," he added.
He said that while Chinese authorities provisionally plan to have the carrier conduct its first trial voyage in August, no definite date has been picked.
"Many factors could affect the timing, including weather condition and general international atmosphere," the official said.
Certain external factors, such as tension in the disputed South China Sea (East Sea), are also possible reasons for the postponement, the Hong Kong paper said.
At the beginning of last month, China's defence minister sought to reassure Asia Pacific neighbours that his country's growing economic and military power was not a threat.
General Liang Guanglie told the annual Shangri-La security conference in Singapore that the modernization of the People's Liberation Army was in line with the country's economic growth and to meet its security requirements.
"We do not intend to threaten any country with the modernization of our military force. I know many people tend to believe that with the wealth of China's economy, China will be a military threat," he said.
"I would like to say that it is not our option. We didn't seek to, we are not seeking to and we will not seek hegemony and we will not threaten any country."
But Liang said the situation in the East Sea where a territorial dispute with Vietnam and the Philippines heated up last month was now stable.
"China is committed to maintaining peace and stability in the South China Sea," he said adding it stood by a 2002 code of conduct signed with members of the Association of South East Asian Nations to resolve peacefully the rival claims over the resource-rich region.
China, Vietnam, the Philippines, Malaysia, Brunei and Taiwan all claim territories in the sea, which covers an important shipping route and is thought to hold untapped oil and gas reserves.
China's claim is by far the largest, forming a vast U-shape over most of the sea's 648,000 square miles (1.7 million square km), including the Spratly and Paracel archipelagos.
Tension also increased with Vietnam last month after Hanoi said a Vietnamese oil and gas exploration ship had its surveying cables cut by Chinese boats. The Philippines also accused of Chinese ships to infringe into this country’s waters since February and shot its fishermen at least once.
The modernization of China's navy in particular has raised concern in the region. Beijing is upgrading its destroyers and frigates to sail further and strike harder.
The Varyag, which a Chinese firm bought from the Ukraine in 1998 for US$20 million, is currently being refurbished by the Chinese navy in the port city of Dalian in northeast China and will be officially launched around October next year.
The US Office of Naval Intelligence has estimated the vessel would be launched as a training platform by 2012 and be fully operational after 2015.
China would be the third Asian country to have a carrier after India and Thailand, something that has caused unease in the region.