Argentine President Cristina Kirchner and Chinese Premier Wen Jiabao hailed 40 years of strong diplomatic ties between their two countries.
At a ceremony in a museum opposite the presidential Casa Rosada mansion, Wen on Sunday called the four-decade mark an "important milestone" and praised the "deepening friendship and trust" between Buenos Aires and Beijing.
Trade between the two states totaled $14.8 billion in 2011. The Asian powerhouse is Argentina's biggest taker of agricultural products and its second largest trade partner.
Kirchner said China had played a "paramount" role in fueling global growth over the past 10 years.
She also stressed that both countries have a "common vision on defending territorial integrity" and acknowledged China's support for Argentina's claim to the disputed Falkland Islands, which are administered by Britain.
Earlier this month, Kirchner demanded that London start talks with Buenos Aires over the archipelago on the 30th anniversary of the end of their war over the territory.
Wen is on a multi-country tour of South America. He is scheduled to sign agreements and meet with Argentine officials and lawmakers Monday before departing later in the day.