BEIJING –  U.S. Treasury Secretary Jacob Lew pressed Chinese leaders over computer hacking and for help with North Korea during two days of talks that ended Wednesday.
Lew's visit to Beijing was the first high-level contact between the two governments in six months as they re-engage following a hiatus during the Chinese leadership transition.
The White House has called for Beijing to take action to stop computer attacks aimed at stealing company secrets. Hundreds of cyberattacks have been traced to China, and a security firm said last month that it found a wave of attacks on 140 companies that originated in a building in Shanghai housing a military unit.
"This is a very serious threat to our economic interests. There was no mistaking how seriously we take this issue," Lew told reporters.
Chinese officials have denied their government is involved and say China also is a victim of cyberattacks.
In talks with Chinese leaders, Lew emphasized that Washington sees a distinction between criminal cyberattacks, which are a common threat, and spying by state-sponsored enterprises, said a senior American official who spoke on condition of anonymity in order to brief reporters. The official declined to say how Chinese officials responded.
On North Korea, Washington wants Beijing to use its status as the North's main source of trade and aid to press Pyongyang to discard its nuclear program.
"We made clear that the U.S. views the provocative actions of North Korea as very serious and we will continue to pursue methods available to change the policy perspective in Pyongyang," Lew said. "We share a common objective of a denuclearized Korean Peninsula and we will continue to discuss it."
Asked whether Washington was considering sanctions that might affect Chinese banks, a senior administration official said the U.S. is exploring its options to influence North Korea's behavior but said U.S. leaders would rather not impose burdens on the Chinese economy.
This week's talks were the start of a series of meetings that will test the potential for cooperation between the world's largest- and second-largest economies. Lew is the U.S. economic envoy to an annual high-level strategic and economic dialogue between Washington and Beijing that is due to hold its next round this summer.
Although the relationship is colored by mutual suspicion, the two sides now discuss an ever-broadening agenda, from military cooperation to food safety. Last year, they swiftly resolved a diplomatic standoff when Beijing agreed to allow a Chinese legal activist, Chen Guangcheng, to leave for the United States after he sought refuge in the American Embassy.
Despite frictions over North Korea, computer hacking and human rights, both sides sounded positive notes during Lew's visit and stressed their wide array of mutual interests.
China's new president, Xi Jinping, said Tuesday that the two sides have "some differences" but "enormous shared interests."
Xi has visited the United States a half-dozen times but also is seen as a nationalist who is willing to defend what he considers China's core interests regardless of the cost to its reputation. Beijing is locked in territorial feuds with Japan and several Southeast Asian nations that threaten to draw in the United States.
On Wednesday, Lew stressed their common interests in a meeting with China's new top economic official, Premier Li Keqiang.
"We have a shared interest in making sure global growth continues," Lew told Li at Beijing's Zhongnanhai compound, where Chinese leaders live and work.
Li said Lew's visit would further "understanding, communication and trust" between the two sides.
Lew also met with his new Chinese counterpart, Lou Jiwei, and the head of China's main economic planning agency. He also spoke with Wang Qishan, a member of the country's ruling seven-member Standing Committee with extensive experience in finance and trade issues who dealt regularly with Lew's predecessors, Henry Paulson and Timothy Geithner.