MATERA, Italy -- Foreign ministers from the G-20 group of nations met in-person for the first time in almost two years here on Tuesday in an effort to get on the same page ahead of the summit in Rome this October.

But unity will not come easy. Reflecting the fault lines between the nations, Russia sent only a deputy foreign minister while China opted to participate only virtually.

The global coronavirus vaccination campaign was a top priority. Roughly 3 billion doses have been administered worldwide so far, but this figure conceals stark regional differences. Africa has given only about 4 doses per 100 people, compared with 97 in the U.S. and 66 in Europe, according to Our World in Data.

Chinese Foreign Minister Wang Yi championed the cause of supplying vaccines to developing countries while touting Beijing's efforts in this arena.

"To date, China has provided over 450 million doses of vaccines to nearly 100 countries," said Wang, who attended the gathering virtually . "We call on countries with the relevant capacity to refrain from imposing export restrictions and excessive hoarding, and do their part in closing the immunization gap."

Wang urged G-20 members to "provide stronger support for developing countries."

Japanese Foreign Minister Toshimitsu Motegi highlighted Japan's contributions through channels including the World Health Organization-backed COVAX program.

Host country Italy, focusing on the theme of multilateralism and global governance, put sustainable development and recovery from the pandemic at the top of the agenda. Multilateralism and international cooperation are the only effective ways to address the coronavirus crisis, Foreign Minister Luigi Di Maio said in his opening remarks.

Climate change was also a major topic. A number of G-20 members, including the U.S., Japan and European countries, have pledged to achieve net zero greenhouse gas emissions by 2050, even as demand for cheap coal power remains strong in developing nations. China, which generates about 30% of global emissions, is under particular pressure to fulfill its obligations as a world power.

Food security was featured on the agenda on its own for the first time at a meeting of top G-20 diplomats, as countries have restricted food exports amid the pandemic even as conditions such as drought have caused famine in developing countries. The ministers issued a joint declaration on addressing hunger and food insecurity.

The meeting emphasized support for Africa in such areas as agricultural development and empowerment of women.

After Group of Seven members came together on countering China at this month's summit, Washington hoped to accelerate this push among the G-20 as well.

Motegi stressed the need for the group to discuss greater transparency for development financing, reflecting ongoing concerns about China's aggressive funding of infrastructure in emerging countries through the Belt and Road Initiative and the risk of debt traps.

But G-20 members are less similar ideologically and economically than the G-7 bloc, and winning support for a push against Beijing is difficult when so many countries depend on China.