The Chinese ambassador to the U.S. warned that China will retaliate if the U.S. issues more restrictions on technology and trade.

Ambassador Xie Feng said that while China does not want a trade war with the United States, it will take action if the U.S. further restricts trade. His comments at the Aspen Security Forum on Wednesday come as tensions remain rocky between China and the U.S. over a suspected Chinese spy balloon that flew over the U.S. earlier this year, as well as sanctions on trade and technology.

“China does not shy away from competition, but the definition of competition by the U.S. side I think is not fair,” Xie said. “The United States is trying to win by keeping China out.”

“This is like restricting the other side to wear outdated swimwear in a swimming contest while you yourself (are) wearing a Speedo,” he added.

When asked whether China will match the U.S with restrictions, he said that is not their hope.

Earlier this month, China restricted exports of high-tech metals gallium and germanium, which are two substances used in computer chips and solar cells. The move was largely seen as a protest against the U.S. sanctions on microchips.

“Definitely it’s not our hope to have a tit for tat,” Xie said. “We don’t want a trade war, technological war. We want to say goodbye to the Iron Curtain, as well as the Silicon Curtain.”

He reiterated that the “world is big enough” for both the U.S. and China to succeed, adding that China is “eager” to have a “stable, healthy relationship” with the U.S.

He said improvements could include increasing the number of flights between China and the U.S. and looking into renewing the countries’ science and technology cooperation agreement.