The Chinese mainland was the world's third-largest defense importer in 2014, according to a report by global consultancy IHS.

The Chinese mainland surpassed the Taiwan region and United Arab Emirates last year, moving from fifth place, ranking only behind Saudi Arabia and India. Russia is currently the largest defense exporter to the Chinese mainland.

The Chinese mainland "continues to require military aerospace assistance from Russia, and its total defense procurement budget will continue to rise very quickly," said Paul Burton, director of defense industry and budgets at IHS Aerospace, Defense and Security, in a statement Sunday.

China is closing a deal to purchase SU-35 fighter jets from Russia, and pilots have arrived in Russia for training, the Global Times newspaper quoted Russian media as saying. China is also negotiating with Russia to purchase Russia's S-400 surface-to-air missile system, said the newspaper.

During a conference last November between the two countries' senior military officials, more agreements on military cooperation were reached, according to Xinhua.

"To tell the truth, there is still a gap between China's armed forces (and foreign counterparts) in terms of overall military equipment," said Fu Ying, spokesperson of China's National People's Congress.

China's defense budget will reach $141.65 billion in 2015, a 10.1 percent increase from last year, but the rate is the slowest in five years.

However, Craig Caffrey, senior defense budget analystwith IHS, in a March 4 report, said the current lower rate of inflation in China puts real growth "around 9 percent, in line with recent years".

"Lagging behind leaves one vulnerable to attacks," said Fu. "That is a lesson we have learned from history."

Seven of the top 10 defense importers are within the Asia-Pacific region. The six others are: India (second), Taiwan province, Australia, Republic of Korea, Indonesia (fifth to eighth) and Pakistan (10th).

Among those, India was the world's largest defense importer and the largest defense market for US exports in 2012 and 2013, until it was replaced by Saudi Arabia last year. The IHS report also projects that South Korea will become a "regional leader" in terms of defense imports.

"I am not sure what level of defense purchase constitutes an arms race," said June Teufel Dreyer, professor of political science at the University of Miami. "However, a number of countries in the region have increased their arms purchases in recent years."

China's defense budget is lower than that of the US, Russia and the United Kingdom as a percentage of GDP. According to the Stockholm International Peace Research Institute, 2 percent of China's GDP went into military spending in 2013, the latest data available. The number for the US was 3.8 percent; Russia was 4.1 percent; and the UK was 2.3 percent.

Part of China's military budget increase was to improve wages and the welfare of the country's 2.3 million military personnel.

The IHS report also said China was the world's eighth-largest defense exporter in 2014. The world's five largest military exporters are the US, Russia, France, the UK and Germany.

In 2014, global defense trade increased for the sixth straight year to $64.4 billion, up from $56.8 billion.

Lu Huiquan in New York contributed to this report.