Beijing: US Treasury Secretary Janet Yellen concluded her four-day visit to China on Sunday, expressing optimism about the future of US-China relations.

Yellen met with Vice Premier He Lifeng and other Chinese officials to discuss a range of issues, including trade, investment, and climate change. The two sides agreed to enhance communication and cooperation on addressing global challenges.

While the visit did not result in any specific breakthroughs, Yellen said that she was encouraged by the open and candid discussions. She said that the two sides had a "shared understanding" of the importance of responsible management of the US-China relationship.

Yellen also acknowledged that there were significant disagreements between the two countries, particularly on trade issues. She said that the US would continue to take steps to protect its national security interests, but that it was also committed to working with China to find areas of cooperation.

"We believe that the world is big enough for both of our countries to thrive," Yellen said. "We need to find ways to coexist and share in global prosperity."

The visit comes at a time of heightened tensions between the US and China. The two countries have been engaged in a trade war for the past few years, and there have been concerns about China's growing military power. However, Yellen's visit suggests that both sides are willing to engage in dialogue and try to find ways to improve relations.

It remains to be seen whether Yellen's visit will lead to any significant breakthroughs, but it is a positive step in the right direction. The two sides need to find ways to manage their differences and work together on issues of common interest. If they can do that, it will be good for both countries and for the world.