A top US commander in Afghanistan has said he needs several thousand more troops to help the Afghans take on a resurgent Taliban and battle other insurgents. But no official plan has been announced. <br/><br/><br/>US President Donald Trump's national security adviser, McMaster today met President Ashraf Ghani and other senior Afghan officials in Kabul to discuss bilateral ties, security, counter- terrorism, reforms, and development, according to a statement on the palace's Twitter account. McMaster met Afghan officials amid questions over the new administration's plans for the military mission in Afghanistan after American forces unleashed a huge bomb there on militants. <br/><br/>The visit by HR McMaster, the first high-level visit by a Trump official, came just days after the US military sparked controversy by dropping a GBU-43 Massive Ordnance Air Blast bomb, one of the largest conventional weapons ever used in combat, during an operation on Thursday against Islamic State militants in eastern Afghanistan. <br/><br/>While military officials said the strike was based solely on tactical needs, it led to speculation that Trump's defence advisers are planning to escalate the war against militants in Afghanistan. Nearly 9,000 US troops are stationed in Afghanistan to train and advise Afghan forces, provide close air support to soldiers on the ground and form a separate counter-terrorism unit that targets Islamic State, al Qaeda and other militant networks.