Chinese President Xi Jinping has warned that no one can "dictate" China's economic development path as the Communist Party marked 40 years of its historic "reform and opening up" policy amid a stern challenge from the United States.
In a speech at the Great Hall of the People, Mr Xi vowed to press ahead with economic reforms but made clear that Beijing would not deviate from its one-party system or take orders from any other country.
Without directly referring to the United States, Mr Xi said China "poses no threat" to any country but warned that it would not be pushed around.
"No one is in a position to dictate to the Chinese people what should or should not be done," China's most powerful leader since Mao Zedong told the party faithful.
"We must resolutely reform what should and can be changed, we must resolutely not reform what shouldn't and can't be changed."
While Mr Xi promised more reforms, he did not offer any specifics.
The US and Europe have long complained of lingering obstacles to fully entering China's massive market while Chinese companies enjoy the benefits of open Western economies abroad.
"We actively promote the construction of an open world economy, build a community of human destiny, promote the transformation of the global governance system, clearly oppose hegemonism and power politics," Mr Xi said.
"China is increasingly approaching the centre of the world stage and becoming a recognised builder of world peace, a contributor to global development, and a defender of the international order."
The commemoration of the reforms enacted under late leader Deng Xiaoping on 18 December, 1978, came as China is locked in diplomatic spats and a bruising trade war with the United States.
The rivals have agreed to a 90-day truce as they seek to negotiate a solution, with the US seeking a reduction in its massive trade deficit, as well as deeper reforms in China, to stop the alleged theft of intellectual property.
China's reforms pulled hundreds of millions of people out of poverty and turned the country into the world's second biggest economy.
But it is currently facing a debt mountain and a slowing economy, which grew by 6.9% last year and the rate is expected by the government to ease to around 6.5% this year.
The ceremony included the awarding of medals to more than 100 individuals whom the party recognised as key contributors to the country's development, from people involved in rural reform and poverty alleviation to China's richest man, Alibaba founder Jack Ma, and retired NBA legend Yao Ming.
Mr Deng's reforms broke with Maoist-style collectivisation that left the nation impoverished and backward.
The poverty rate among the rural population dropped to 3.1% last year from 97.5% 40 years ago.
China now boasts the most dollar billionaires in the world with 620, according to Shanghai-based magazine publisher Hurun Report.
But the economic transformation has not brought changes to the Communist Party-controlled political system, with authorities harshly cracking down on the Tiananmen protests in 1989 and activists complaining of a deterioration of human rights in recent years.