WASHINGTON, DC -- Defense Secretary Jim Mattis said he and the top U.S. diplomat affirmed with high-ranking Chinese officials today that North Korea's nuclear missile program is a threat to peace and security in the Asia-Pacific region, June 21, 2017.

Mattis spoke at the State Department with Secretary of State Rex Tillerson, after they hosted the first iteration of the U.S.-China Diplomatic and Security Dialogue.

"We also affirmed our strong commitment to cooperate, including through the U.N. to realize our shared goal of denuclearization of the Korean Peninsula," Mattis said. "Meanwhile, we will continue to take necessary measures to defend ourselves and our allies."

The dialogue with China's State Councilor Yang Jiechi and Gen. Fang Fenghui, chief of the Chinese joint staff department, is a result of the summit in April between President Donald J. Trump and Chinese President Xi Jinping at Trump's Mar-a-Lago estate, Mattis explained.

Mattis Committed to U.S.-China Defense Relationship

The talks were a "unique opportunity," Mattis said, for the United States and China to engage in "philosophical-level discussions" about the way ahead on shared security interests.

The United States seeks a constructive and results-oriented relationship with China in which differences are managed when they arise, Mattis said.

"I'm committed to improving the U.S.-China defense relationship so that it remains a stabilizing element in our overall relationship," Mattis said. "Our two nations can and do cooperate in mutually beneficial ways."

The United States and China agreed to explore new areas of military-to-military cooperation, Mattis said. That includes, he explained, exchanging officers to improve transparency and mutual understanding.

"We welcome the opportunity to engage with the Chinese counterparts on strategic topics to discuss our differences and will now press forward where we can work together," the defense secretary said.

Decreasing South China Sea Tensions

Discussions also focused on freedom of navigation through the Asia-Pacific region, and the peaceful resolution of disputes in the maritime space, Mattis said.

"We discussed ways to decrease tension and reduce risk in the South China Sea," he said, adding, "As we maintain open dialogue on this topic, the United States will continue to fly, sail and operate wherever international law allows."

Chinese Contributions to Global Security

The United States and China "decided to adopt greater coordination to face the global threat posed by terrorism," Tillerson said.

Those efforts, he explained, include China helping Iraq as that Middle Eastern country seeks to defeat the Islamic State of Iraq and Syria.

"We will be looking to China to help the Iraqi government in specific, meaningful ways to ensure the country's long-term stability and economic growth as it battles ISIS and begins its long process of rebuilding," Tillerson said.