China's annual high-level political meetings opened Thursday with a minute's silence for the victims of the coronavirus pandemic and a threat to hit back at the US in an escalating blame game over the disease.

Delayed by two months because of the outbreak, the Chinese People's Political Consultative Conference (CPPCC) - a largely ceremonial advisory body - began its first session a day before the start of the country's most important legislative congress.

More than 2,000 delegates from across the country bowed their heads in silence after singing the national anthem in Beijing's Great Hall of the People. The virus emerged in the central city of Wuhan before spreading around the world, infecting more than five million people and killing over 328,000, including more than 4,600 in China.

President Xi Jinping and the rest of the 25-member Politburo - the Communist Party's top leadership body - were in the middle of the central stage, the only attendees not wearing face masks. State television showed hundreds of masked delegates in black business suits walking up the steps of the Great Hall shortly before the session began.

Known as the "Two Sessions", the yearly gathering of the CPPCC and the National People's Congress (NPC) involves thousands of delegates flocking to the capital for intensive meetings to discuss policy.

Originally scheduled for March, this year's meetings will be squeezed into six days and end May 28 instead of the usual 10 days, a parliament spokesman said. Delegates were required to undergo multiple nucleic acid tests for the virus before taking part in the sessions, and must wear face masks throughout.

The number of journalists allowed into the Great Hall has been massively reduced with many press conferences and delegate interviews moved online as a virus prevention measure.

On Friday the NPC will open in highly choreographed meetings to rubber-stamp bills, budgets and personnel moves.

Ministers will also reveal key economic targets, military budgets and other strategic priorities that shed a light on the thinking of Communist Party leaders, as China emerges from the devastating aftermath of the coronavirus.