China pledged to boost military spending further at the opening of the nation's annual session of parliament on Monday, laying the groundwork for achieving powerful President Xi Jinping's goal of modernizing its military forces to "world class" status.

The government of the world's second-largest economy also expressed eagerness to vigorously respond to U.S. trade restrictions, as it faces increased protectionist sentiment in the United States under the presidency of Donald Trump.

On the first day of the National People's Congress, Premier Li Keqiang, who delivered a report mapping out policy directions for 2018, said the defense budget will rise by 8.1 percent this year from 2017 to 1.1 trillion yuan (about $173.6 billion).

"Faced with profound changes in the national security environment, we must...firmly uphold the guiding position of (President) Xi Jinping's thinking on strengthening the armed forces as we develop national defense and the armed forces," Li said in his report.

"We will continue to reform national defense and the armed forces, and build strong and solid modernized border, coastal, and air defense," Li said, with fears growing across the region about the Asian power's growing assertiveness in contested waters.

Xi has promised to make China's military forces "world class" by the middle of the century. The nation's military budget for 2017 exceeded 1 trillion yuan for the first time.

On the economic front, the government set growth and inflation targets for 2018 at around 6.5 percent and about 3 percent, respectively, unchanged from 2017.

Economic growth in China accelerated for the first time in seven years in 2017, reaching 6.9 percent from the previous year, official data showed in January.

"China's economy is transitioning from a phase of rapid growth to a stage of a high-quality development," Li said.

Xi, who began his second five-year term as China's leader in October last year, has vowed to build a "moderately prosperous society," where all citizens can enjoy comfortable lives before 2021, the 100th anniversary of the Communist Party's founding.

"For the government to deliver this year, we must act on Xi Jinping's economic thinking for new-era socialism with Chinese characteristics," Li said.

But many analysts are skeptical about whether the Chinese economy will continue to expand at the same pace, as Xi's government is likely to carry out additional measures to restrain the overheated property market and protect the environment.

Li, meanwhile, pointed out that China's economic growth may be dragged down by global economic uncertainties, in an apparent allusion to the recent U.S. decision to impose tariffs on steel and aluminum imports.

"We can expect continued recovery of the global economy, but there are also many factors that bring instability and uncertainty. The policy changes of the major economies and their spillover effects create uncertainty; protectionism is mounting and geopolitical risks are on the ascent," Li said.

"China calls for trade disputes to be settled through discussion as equals, opposes trade protectionism and will resolutely safeguard its lawful rights," he added.

Trump said Thursday that the United States will impose tariffs of 25 percent on steel imports and 10 percent on aluminum, apparently targeting China.

Li also said in his report that the government will take necessary steps to encourage new businesses and improve the quality of education, as well as implementing the "Healthy China" strategy toward the 2022 Olympics in the nation's capital.

"We will make thorough preparations for the Beijing Winter Olympics and Paralympics. Multiple channels will be used to increase sports venues and facilities available for the general public," he said. "If our people are fit and healthy, are strengthening social morality, and are striving to succeed, our country is certain to thrive and progress toward prosperity."

During the parliamentary session, the country's Constitution is set to be revised to effectively enable Xi to seek a third term in 2022.

In addition, the first constitutional revision in more than a decade may include the incorporation of Xi's political thought into the nation's supreme law, a move that would make China's long-established collective leadership system a mere formality.

Issues such as government personnel movements, a structural reform plan for the party and state institutions and financial regulation will also be on the agenda.

"All aspects of government performance will be improved," Li said. "Taking big and setting ambitious goals but taking little action to achieve them will not be tolerated; nor will sitting around in a government post and getting nothing done."

As for government personnel, Wang Qishan, a Xi confidant who was replaced in October as head of the Central Commission for Discipline Inspection in line with the party's informal retirement age, is tipped to become the country's vice president.