South Korean President Lee Myung-bak and his Brazilian counterpart Luiz Inacio Lula da Silva pledged Thursday to bolster bilateral trade and investment.

The two presidents made the pledge during their talks on the sidelines of the G20 Economic Summit in Seoul, according to Lee's office Cheong Wa Dae.

Noting that Brazil is the biggest trade and investment partner among Latin American countries, Lee suggested working together to double their two-way trade and investment in five years. Lula showed support for the idea, and asked for more cooperation on science technology, Cheong Wa Dae said.

Lee asked for the Brazilian government's support for a consortium of South Korean firms bidding for Brazil's infrastructure-building projects including bullet train construction.

He also extended congratulations to Dilma Vana Rousseff, Brazil's female President-elect, who accompanied Lula on his trip to Seoul. She is to take office next January.