"The agreements, which come at a time when the Delta variant is posing a rising risk to health systems, will begin to make 110 million doses immediately available to participants of the COVAX Facility, with options for additional doses," GAVI said.
Ukraine received its first batch of 215,000 Sinovac doses in March to boost its vaccination programme, which has lagged behind many other European countries and it has so far relied on a single batch of AstraZeneca vaccines from India.
"The vaccines of the Chinese company Sinovac Biotech can be trusted," it said.
Turkey has so far delivered 16.5 million vaccine doses nationwide, including more than 7 million people who have received a second dose of the shots developed by China's Sinovac Biotech.
A total of 2.8 million doses of the Pfizer vaccine have arrived in Turkey, with that number expected to reach 4.5 million in the coming days, Health Minister Fahrettin Koca said on Wednesday.
Foreign Minister Marcelo Ebrard said earlier in the week that Mexico was upping its orders from China to make up for a vaccine shortfall and would request 22 million more doses.
Mexico ordered an additional 10 million doses of Sinovac, in addition to the previously ordered 10 million doses, which are due to arrive between March and May.
Ebrard said Mexico has put in an order for an additional 10 million doses of China's Sinovac COVID-19 vaccine to be delivered between May and July, on top of the 10 million already ordered, which are due to arrive between March and May.
Ukrainian pharmaceutical company Lekhim - one of Sinovac's partners - has an agreement with the manufacturer to deliver 5 million doses of the vaccine in Ukraine, including 1.9 million via a state procurement scheme.
Ukraine started COVID-19 vaccinations in late February but only 19,118 first shots had been given by March 9.
Malaysia began its vaccination drive on Feb. 24 using a shot developed by US drugmaker Pfizer and German partner BioNTech, as it tries to rein in a spike in infections and help revive an economy that recorded its worst slump in more than two decades last year.
Sinovac signed a deal with Malaysia's Pharmaniaga, which will carry out a fill-and-finish process for the vaccine's distribution in Malaysia, before later manufacturing it locally.
Hong Kong's government said in early February that it was exempting Chinese drug maker Sinovac from publishing results of its third phase clinical trials in medical journals due to the "urgency" for vaccination.
The city's Health Secretary Sophia Chan has the final decision on whether to approve the Sinovac vaccine.
Mexican officials had communicated with colleagues in Chile last week to get feedback on the Sinovac vaccine, and would also do so with Colombia's health ministry later on Tuesday.
The importer, Ukraine-based Lekhim, cited delays in obtaining an export licence from the Chinese government and the late adoption by Ukraine's parliament of a special vaccine registration law.
Lekhim, which has a deal to deliver 1.9 million doses to the Ukraine government from March.
Turkey has reported more than 2.3 million infections since March and still reports around 10,000 new cases and 170 deaths each day after a month of weekend lockdowns and nightly curfews.
We spent around 10 months in white overalls, supporting people as they struggle for life. Health workers know very well that this situation cannot be taken lightly and that the vaccine is needed.
This 50% is good, is it? All the (criticism) I got for my comments, and now they are seeing the truth. Four months of being lambasted because of the vaccine.
Brazil's government closed a deal with the Butantan Institute to buy up to 100 million doses of the Chinese vaccine.