China plans to build a 100-bed medical centre in Liberia to combat Ebola, officials announced on Thursday, after criticism that the country is not doing enough to fight the disease.

China will send 1,000 aid workers to Ebola-affected areas “in the months to come”, and has already sent 252 people to the three hardest-hit countries – Guinea, Liberia and Sierra Leone – since the deadly virus broke out in March, the official newswire Xinhua reported on Wednesday.

Foreign ministry spokesman Hong Lei elaborated on the announcement at a regular press conference on Thursday afternoon. “In Liberia, we will build a 100-bed medical centre,” he said. “On 9 November, 160 medical workers will set off for Liberia.” He added that 320 additional workers would arrive at the centre at a later date.

“All the construction materials, construction workers and medical workers are in place,” he said. The centre is scheduled to open in 30 days.

Hong said: “Many countries have evacuated their diplomatic personnel, aid workers and enterprises from affected areas. However, there are still several thousand Chinese people working there.”

Hong’s comments partially contradict earlier reports that scores of Chinese workers have fled Ebola-affected countries since the spring. According to the Wall Street Journal, the state-backed China Henan International Cooperation Group pulled most of its workers from an $80m road-building project in Liberia in August. China’s commerce ministry estimated then that 20,000 Chinese people lived in affected countries; since then, the number may have halved.

Jim Yong Kim, president of the World Bank, told reporters this week that “many countries in Asia who could help simply are not [helping], especially when it comes to sending health workers”. He did not mention China by name.

Last month Brett Rierson, the World Food Programme’s China representative, urged China to do more to fight the disease. “No one’s been willing to do anything big yet,” he said.

The US secretary of state, John Kerry, said last month that the US and China, despite their many disagreements, hoped to work together to curb the virus. China has sent a total of $122m (£76m) to combat Ebola, according to the China Daily. The US has pledged more than $1bn.

“China and Africa are good brothers who hold hands,” Hong said. “When Africa is hit by Ebola, the Chinese government and people feel like they’re suffering, so we offer assistance to the best of our abilities. China is a developing country, but we are doing everything we can.”