On his first official visit to Venezuela, the Turkish leader blasted sanctions imposed on Maduro and many of his top officials by the United States, with which his government also has tense relations.
"Trade restrictions and sanctions are wrong," Erdogan said, warning that such measures would only deepen "instabilities."
"You cannot punish an entire people to resolve political disagreements," the Turkish leader said, according to an official translation of his speech to a business forum.
Earlier, Erdogan laid a wreath at the tomb of Venezuela's founding father Simon Bolivar, and Maduro also presented him with a replica of the revolutionary leader's sword.
Business links
But the key highlight was Erdogan's speech at the business forum.
With oil production in a tailspin the socialist president has invited Turkish businesses to invest in exploiting a vast mining reserve known as the Arco del Orinoco in the south of the country, an area with considerable gold, diamond and coltan reserves.
Non-oil trade between the two countries this year reached 800 million dollars, according to Caracas, a not insignificant figure given its serious liquidity problems.
Maduro said Turkish businesses intend to invest some 4.5 billion euros in its OPEC partner.
"We are going to cover the majority of Venezuela's needs, we have that strength, I would like to highlight this fact," Erdogan told business leaders.
The South American country has suffered from economic woes since 2014, when a crash in the price of crude prompted a crisis that has sparked an exodus of some two million people.
"I want my visit to be considered as a symbol of collaboration of the Turkish people with the people of Venezuela," said Erdogan.
Erdogan's trip had been announced, though without a specific date, during a September 21 visit to Caracas by his foreign minister Mevlut Cavusoglu.
Maduro travelled to Turkey last July for the inauguration of Erdogan's inauguration at the start of a new five-year term as president of Turkey, a country he has led since 2003.
