DALIAN, China — A top Chinese leader made an unusually public effort on Tuesday to ease trade tensions somewhat with the United States, woo foreign investors and reassure his own country’s citizens that their economy remained on track.

In meetings during the World Economic Forum in the Chinese port city of Dalian, Premier Li Keqiang, China’s No. 2 official, promised to cut tariffs, loosen limits on foreign investment, protect intellectual property and allow foreign companies to apply for China’s generous subsidies for research and development. He made many of those comments in a rare question-and-answer session in the afternoon with executives from Japan, the United States and other countries.

He also said that China would allow foreign financial services companies into its market a year earlier than previously promised, and that it would rewrite many rules on foreign investment.

“We will move up the lifting of foreign capital limits in securities, futures and life insurance, from 2021 to 2020,” Mr. Li said in a morning speech, prompting a burst of applause from a crowd that appeared to include many bankers and others in finance. “This shows China’s commitment to opening up.”