SHANGHAI -- President Xi Jinping on Monday promised to further open China to foreigners by expanding imports, lowering tariffs and relaxing market access -- an apparent bid to counter criticism from U.S. President Donald Trump and others regarding Beijing's trade and business practices.

In a speech at the opening ceremony of the China International Import Expo, Xi predicted the value of the country's "imported goods would reach $30 trillion, while imported services would top $10 trillion over the next 15 years."

Xi's remark comes amid heightened trade tensions between Beijing and Washington. The U.S. government has imposed tariffs on Chinese goods worth $250 billion. China has retaliated by imposing tariffs on American goods worth $110 billion.

Xi reiterated Beijing's stance to support global free trade systems. China, he said, will promote international cooperation on both bilateral and multilateral levels.

The president added, "A winner-takes-all mentality is a dead-end in today's world."

In a bid to ease tensions, Beijing and Washington are trying to arrange for Xi and Trump to meet on the sidelines of a meeting of leaders from the world's 20 industrial and emerging powers to be held at the end of this month in Argentina. Xi did not explicitly mention the trade war with the U.S. nor Trump during today's speech.

The Chinese President also said he will further open the health care and education sectors to foreign investment and impose more costs on offenders of intellectual property rights.

More than 3,600 companies from about 170 countries and regions are expected to attend the expo, where they are to hold business talks with China's provincial governments and state-owned enterprises.

Xi has repeatedly showed Beijing's willingness to expand imports from the U.S.

To boost imports, regional governments are believed to have prodded Chinese companies to attend the event and impose purchase quotas on them.

The Shanghai expo is showcasing Beijing's efforts to ease the trade war the U.S. and promoting China as a big buyer of American products.

Washington did not send officials, but about 180 American companies -- the third largest number after Japan and South Korea -- are attending the fair.

This year marks the 40th anniversary since China began reforming its economy and opening its markets to overseas companies.

In the past four decades, Xi said, "what the Chinese people have gone through -- regarding development -- has been epic."

Akihide Anzai contributed to this report.