US Vice President Joe Biden Monday began a four-day visit to India to discuss economic ties, trade, energy, climate change and defence cooperation, US officials said according to dpa. He is to also discuss regional security, including the conflict in Afghanistan, with Indian leaders. Biden was expected to address New Delhi's concerns about the withdrawal of US troops from Afghanistan and upcoming talks with the Taliban. He is to meet President Pranab Mukherjee and Premier Manmohan Singh on Tuesday, the main day of talks.