WASHINGTON — Treasury Secretary Janet L. Yellen called Thursday for a “constructive” and “healthy” economic relationship between the United States and China, in which the two nations work together to tackle challenges like climate change.

Ms. Yellen’s comments, in a speech at the Johns Hopkins University School of Advanced International Studies, struck a remarkably positive tone about the US-China relationship after months of heightened tensions between the two nations, which have the largest economies in the world.

Ms. Yellen stressed the importance of securing US national security interests, as well as protecting human rights. She also stressed that the targeted actions the US had taken against China, such as isolating it from the world’s most advanced semiconductors, are solely aimed at protecting US national security.

China has criticized US restrictions on its technological development, saying they are illegal and a brazen effort to try to weaken the Chinese economy. Ms. Yellen tried to allay those concerns.

“These national security actions are not designed to give us a competitive economic advantage or stifle China’s economic and technological modernization,” Ms. Yellen said. “Although these policies may have economic impacts, they are driven by direct national security considerations.”

He also emphasized the strength of the US economy, noting that the economic output of the United States is still much higher than that of China.

Relations between the two nations have been tense recently, including a diplomatic flare-up in February after a Chinese spy balloon traversed the United States before being shot down over the Atlantic Ocean. Both Republicans and Democrats continue to portray China as an obvious economic rival and security threat.

Tensions also remain high over the future of Taiwan, which China claims as its territory. And many US officials have lost patience with the idea of ​​bringing China into the rules-based international system, arguing that efforts to do so in recent decades have failed to adequately improve its business practices.

But Ms Yellen argued that competition between the US and China could lead to mutual improvement, within certain parameters.

“Sports teams perform at a higher level when they consistently face the best opponents,” he said. “But this kind of healthy competition is only sustainable if it’s fair to both parties.” China has long used government support to help its companies at the expense of foreign competitors, and its industrial policy “has grown more ambitious and complex,” Yellen said.