TOKYO (AFP) - Afghan President Hamid Karzai launched a sales pitch on Friday for his war-torn countrys rich mineral resources, calling for major aid donor Japan to invest in mines. Karzai also said he was planning to meet with representatives of Japans major trading house Mitsubishi Corp. later in the day to discuss possible future exploitation of the deposits. Afghanistans mining minister said Thursday that mineral deposits in his country could be worth up to three trillion dollars, tripling a US estimate which emerged earlier this week. The results of the US geological survey said Afghanistan had huge reserves of lithium, iron, copper, gold, mercury, cobalt and other minerals potentially worth nearly one trillion dollars. So the prospects of Afghanistan is massively great and good, Karzai said. Whereas Saudi Arabia is the oil capital of the world, Afghanistan will be the lithium capital of the world. And Japan is welcome to participate in the lithium exploration in Afghanistan, he said of the material used in batteries for a range of electronic devices. Morally, Afghanistan should give access as a priority to those countries that have helped Afghanistan massively in the past few years, he said on the latest day of a visit to Afghanistans biggest donor after the United States. Japan last year pledged up to five billion dollars in aid by 2013 to rebuild the impoverished country, where US-led and then multinational forces have been battling Taliban insurgents since late 2001. Karzai on his first visit to Tokyo since he started his second term in November after an election widely criticised for vote-rigging thanked new Prime Minister Naoto Kan on Thursday for Japans support. Kan however reminded Karzai of the need for better governance in his corruption-riddled nation, saying the aid must be used to the benefit of the Afghan people and to achieve global peace. Asked how to rebuild security in Afghanistan, Karzai said he is working to build up Afghan forces, Afghan police and continue to fight extremism. He also said another approach was engaging grassroots Taliban fighters who are not hardcore members of extremist groups, to encourage them to lay down their arms and return to civil society.