<br/>US President Barack Obama made a telephone call to Prime Minister Dr Manmohan Singh to express concern over the recent attack on the Indian Embassy in Kabul. In a statement, White House said Obama, on whose invitation the Prime Minister is visiting Washington next month, also looks forward to receiving Dr Manmohan Singh in the US capital. The US President talked with the Prime Minister on Saturday, a day after the Indian leader called him to congratulate on winning the Nobel Peace Prize for the year 2009.<br/>