WASHINGTON, July 8 -- Former U.S. Secretary of State Colin Powell on Wednesday stressed the importance of U.S.-China cooperation and dismissed the assertion that China will be a military threat to the U.S.

"I do not think China will be a military threat," Powell said in a lecture at the Library of Congress in Washington. "It's not in their interest to be a military threat to the United States of America."

Powell encouraged the U.S. to work with China, saying that such cooperation will not result in a military conflict.

The former top American diplomat in George W. Bush's administration said China's economic development in recent decades is "astonishing" and China is making efforts to invest in its future.

The U.S. has to have a proper relationship with China, Powell said, adding that "it is the most important relationship."

Another speaker of the lecture, former U.S. Secretary of State Madeleine Albright, shared Powell's views on the importance of U.S.-China ties.

Albright said there has never been a time in history that two major powers have been so dependent on each other and their economies so intertwined.

The cooperation part of U.S.-China relations is very important, said Albright, emphasizing that "it is the essential relationship."

At the invitation of U.S. President Barack Obama, Chinese President Xi Jinping will pay a state visit to the U.S. in September.