"It is conducive to uphold the authority of the Central Committee of the party with comrade Xi Jinping at the core and also to unify the leadership", said Mr Zhang, spokesman for the National People's Congress (NPC), China's Parliament, a day before it was due to begin its annual session.
He said he was seeking to "mobilize all the sons and daughters of (ethnic Chinese) to work together for the greater national interests and the realization of the Chinese Dream", referring to Xi's nationalist vision of China as the pre-eminent global power.
U.S. President Donald Trump (L) and China's President Xi Jinping walk along the front patio of the Mar-a-Lago estate after a bilateral meeting in Palm Beach, Florida, U.S., April 7, 2017.
Trump's announcement on Thursday sparked a flurry of counter-threats from other nations but its main trade rival, China, had avoided any overt warnings of potential retaliation until now.
Liu He, director of the General Office of the Central Leading Group for Financial and Economic Affairs, met with senior U.S. economic officials, including Treasury Secretary Steven Mnuchin, for in-depth trade talks before wrapping up his USA trip on Saturday.
Iran, Syria to continue attacking 'terrorists' in Damascus suburbs: agency
Hamza Birqdar, the military spokesman, said the insurgents had thwarted attacks by pro-government forces trying to advance. Pope Francis described Syria as "martyred" on Sunday, calling for aid access and an immediate end to violence.
China's legislature will hold an annual session starting Monday that will grant Xi a second five-year stint as president - and also likely scrap the constitution's limits on holding the office, clearing the way for him to rule for life.
China is predicting a slowdown in growth in 2018.
The growth target - down from last year's "6.5 per cent or higher if possible" - reflects Beijing's promises to pursue more sustainable growth based on domestic consumption instead of exports and investment.
Li promised progress on an array of politically challenging plans including the restructuring or bankruptcy of "zombie enterprises", or money-losing by politically favored companies that are kept afloat by loans from government banks. It announced an 8.1 percent increase for the defence budget to 1.11 trillion yuan ($175 billion) this year, giving the world's largest armed forces a boost after spending growth slowed in the previous two years.
The right way to handle trade frictions is to make the cake of cooperation bigger and find solutions acceptable to both sides through dialogue, said Zhang, who once served as Chinese ambassador to the US. He said the military would "firmly and resolvedly safeguard national sovereignty, security and development interests".
During the remarks, Trump praised Xi as "a great gentleman" and added: "He's the most powerful (Chinese) president in a hundred years".