ASSOCIATED PRESS, AGENCE FRANCE-PRESSE BLOOMBERG and XINHUA in Buenos Aires

China will invest more than US$19 billion in Argentina over the next 10 years, deepening trade links between the world's fastest-growing economy and South America's second-largest, Argentine officials say.

The announcement of the trade and investment agreements came on Tuesday as President Hu Jintao started a two-day visit to Argentina, part of a Latin American tour widely seen as an effort by mainland authorities to expand the country's economic presence in the region.

Argentine officials said the multibillion-dollar investments would be made in energy production, infrastructure and Argentina's railway system, in the largest bilateral trade accord for the country since its 2001-2002 economic crisis.

"Our aim is to strengthen this relationship despite the distances [between the countries]," Argentine President Nestor Kirchner said.

Mr Hu said China and Argentina agreed to upgrade bilateral relations from a "full-range co-operative partnership" to a "strategic partnership".

"We have decided to establish and develop a strategic partnership, and our friendly ties will grow comprehensively on a new basis," Mr Hu said after talks with Mr Kirchner.

Mr Hu also made a veiled reference to Taiwan, saying China and Argentina both agreed to respect each other's territorial integrity.

"The goals will be to strengthen strategic co-operation and continue the firm reciprocal support in terms of sovereignty, such as the territorial integrity of both countries," he said.

Welcomed to the country by dozens of children waving the two nations' flags at Buenos Aires airport, Mr Hu and his official delegation took a 50-car convoy into the capital.

Argentina laid out maximum civilian and military honours for the visit, with a cavalry guard escorting Mr Hu and his wife, Liu Yongqing , to government headquarters for their meeting with Mr Kirchner.

The largest investments signed between the two countries included a Chinese pledge to invest US$8 billion to expand Argentina's railroads, US$6 billion over five years in construction projects and US$5 billion in oil exploration.

Other projects included investment in communications and satellite technology, which raised the total investment figure to US$19.7 billion, according to Argentine and Chinese officials.

Mr Hu is due to leave Argentina today for the annual summit of the Asia-Pacific Economic Co-operation forum in Santiago, Chile.