Iran's president said Tuesday he has "serious doubts" that his country is supplying weapons to Taliban insurgents in Afghanistan, refuting allegations by some Western officials that Iran is arming the militants. Speaking during his first-ever visit to Afghanistan, President Mahmoud Ahmedinejad called Iran's eastern neighbor a "brotherly nation" whose stability is paramount for the region. When asked if Iran is supplying weapons to the Taliban by a reporter from Voice of America, a US-funded outlet, Ahmedinejad laughed and said the United States doesn't want Afghanistan and Iran to be friends. "The same allegation are made in Iraq. They are saying that they discover some weapons," Ahmedinejad said at a news conference with Afghan President Hamid Karzai. "What is the reason why they are saying such things? Iran is a big country. I have serious doubts about this issue."