China's economic growth sank to a new multi-decade low of 6.1 per cent in 2019 as consumer demand weakened and Beijing fought a trade war with Washington.

Government data Friday showed growth was down from 2018's 6.6 per cent, already the lowest since 1990. Economic growth in the three months ending in December held steady at the previous quarter's level of six per cent.

Chinese exporters have been battered by U.S. President Donald Trump's tariff hikes in a fight over Beijing's technology ambitions and trade surplus, though the overall impact on China's economy has been smaller than some forecasters expected.

The economy faces "downward pressure" and "instability sources and risk points" abroad are increasing, the government said in a statement.

The head of the country's statistics bureau said China will maintain a proactive fiscal policy and a prudent monetary policy in 2020 and roll out more support measures this year.

China does not deliberately pursue high economic growth and it is normal for gross domestic product (GDP) growth to fluctuate, Ning Jizhe, head of the National Bureau of Statistics, told a news conference in Beijing following the release of the economic data.

Negotiators this week signed an interim trade deal under which Washington agreed to cancel additional planned tariff hikes and Beijing committed to buy more American farm exports. Tariff hikes already imposed by both sides remained in place.

Economic growth for 2019 was at the low end of the ruling Communist Party's official target of six to 6.5 per cent. The party is trying to steer China to slower, more manageable growth but an abrupt downturn in activity and the clash with Washington have forced the ruling party to step up government spending and take other measures to support growth.

Growth in retail spending, which Chinese leaders are trying to nurture in order to reduce reliance on trade, decelerated to eight per cent over a year earlier, down from 8.2 per cent in the first three quarters. E-commerce spending rose 16.5 per cent.

Factory output rose 5.7 per cent over 2018, down from 6 per cent for the first six months of the year.