China will strengthen its intelligence sharing and cooperation in joint investigations with the United States to fight rampant transnational crimes, a senior official from the Ministry of Public Security said.

The two countries will enhance information exchanges and carry out joint investigations and actions to smash cross-border criminal gangs, said Zhu Yuxiang, deputy director at the ministry's International Cooperation Department.

In addition, they will set up a joint working team for some major or individual cases, including terrorism activities, cybercrime or illegal immigration and focus on personnel training to improve their capabilities, he said.

Due to the rapid development of the internet and simulation of economic interests, cross-border crimes - including terrorist and violent crimes, cybercrime or illegal immigration between China and the US - have been on the rise, posing a threat to people's lives and regional security.

"There has been increasing demand for judicial assistance between the two countries, and most of the requests, including case investigations and locating or arresting suspects, were responded to and carried out immediately," he said.

In June, Zhang Yingying, a visiting Chinese scholar, went missing in Champaign, Illinois, south of Chicago. A local man, Brendt Christensen, has been charged with abducting and killing the student.

Christensen, who this year earned a master's degree in physics, was arrested by FBI agents and charged.

Zhu said China has attached great importance to the case and immediately offered relevant evidence to US investigators. "We will promptly exchange information with our US counterparts and keep close contact with them until the suspect is brought to justice."

Fu Xingchao, a senior official at the ministry's International Cooperation Department, said some progress has been made between China and the US to combat transnational crimes.

On Tuesday, Chinese police handed a US fugitive over to US law enforcement officers at Shanghai Pudong International Airport.

The male fugitive, involved in a car theft in the US, had fled to Shanghai, where he had been working as an English teacher since November 2009. He was not known to have committed an unlawful act during his time in Shanghai, police have said.

The repatriation was demanded by US law enforcement authorities and was the latest result of China-US cooperation in chasing fugitives and illicit money since the countries' first law enforcement and cybersecurity dialogue in October.

Chinese police played their part by locating and capturing the fugitive after receiving a notice from the US in August.

Hong Daode, a law professor at China University of Political Science and Law, said China-US law enforcement security is an important part of the bilateral relationship.

"Both sides should insist on tackling conflicts through dialogue and put aside their political and legal differences," he added.