Chinese President Hu Jintao has met Cuban leader Fidel Castro, as the two communist countries pursue closer ties.
Castro (r) is still largely immobile after a fall last month
The visit is being seen in the Cuban media as a display of solidarity from a faithful ally, years after the collapse of Cuba's former benefactor, the USSR.
But the BBC's Stephen Gibbs in Havana says that despite both being officially communist the two states are moving in opposite directions.
President Hu is pushing privatisation, while Cuba is seeing recentralisation.
Our correspondent says it is not expected that differences in style or ideology will be stressed by either side in the coming days.
On arrival Mr Hu was swept off for talks with Mr Castro behind closed doors in Havana's Palace of the Revolution.
The Cuban leader is still in a wheelchair after breaking his knee and arm in a fall in October.
Mr Hu praised the "heroic Cuban people".
"We sincerely wish the Cuban people do not let up in their advance on the road of socialist construction," he said in a written greeting on his arrival.
But our correspondent says it is not communism but ferrous nickel that has really brought President Hu to Cuba. China is looking to invest heavily in an unfinished Soviet nickel mine on the island.
Nickel is one of Cuba's key exports and a vital commodity for China's booming economy.
Deals on tourism and telecommunications are also expected to be agreed by the large delegation of businessmen travelling with the Chinese president.
Cuba's economy is currently facing difficulties following a decline in foreign tourism since 2002, periodic hurricanes and the increasing costs of importing oil.
Behind the scenes it is also expected that military ties will be strengthened.
The Havana visit is the last leg in President Hu's first trip to Latin America,
which has taken him to Brazil, Argentina and to Chile, where he
attended an Asian Pacific Economic Cooperation summit.
Among those Cubans most looking forward to catching a glimpse of Mr Hu, our correspondent says, are around 2,000 descendents of Chinese labourers who came to work in Cuba's sugar industry in the 19th Century.