AFP, Hiroshima :US Secretary of State John Kerry and G7 foreign ministers today called for a “world without nuclear weapons”, citing North Korea’s sabre-rattling as a key challenge to achieving that goal.”We reaffirm our commitment to seeking a safer world for all and to creating the conditions for a world without nuclear weapons in a way that promotes international stability,” the group said in their “Hiroshima Declaration”, after a landmark visit to the Japanese city’s atomic bomb memorial.”This task is made more complex by the deteriorating security environment in a number of regions, such as Syria and Ukraine, and, in particular by North Korea’s repeated provocations,” it added.On Saturday, Pyongyang said it had successfully tested an engine designed for an inter-continental ballistic missile (ICBM) that would “guarantee” an eventual nuclear strike on the US mainland.It was the latest in a series of claims by North Korea of significant breakthroughs in both its nuclear weapons and ballistic missile programmes.The G7 statement came as ministers wrap up their final day of meetings with discussions focused on global hotspot issues including terrorism and other security threats as well as instability in the Middle East, and the refugee crisis.John Kerry on Monday called his visit to a memorial to victims of the 1945 U.S. nuclear attack on Hiroshima “gut-wrenching” and said it was a reminder of the need to pursue a world free of nuclear weapons.The first U.S. secretary of state to visit Hiroshima, Kerry said President Barack Obama also wanted to travel to the city in southern Japan but he did not know whether the leader’s complex schedule would allow him to do so when he visits the country for a Group of Seven (G7) summit in May.Kerry toured the Hiroshima Peace Memorial and Museum, whose haunting displays include photographs of badly burned victims, the tattered and stained clothes they wore and statues depicting them with flesh melting from their limbs.”It is a stunning display. It is a gut-wrenching display,” he said. “It is a reminder of the depth of the obligation everyone of us in public life carries … to create and pursue a world free from nuclear weapons,” he told a news conference.After the tour by Kerry and his fellow G7 foreign ministers, the group issued a statement reaffirming their commitment to building a world without nuclear arms but said the push had been made more complex by North Korea’s repeated “provocations” and by worsening security in Syria and Ukraine.The ministers from Britain, Canada, France, Germany, Italy, Japan and the United States laid white wreaths at a cenotaph to the victims of the Aug. 6, 1945, bombing, which reduced the city to ashes and killed some 140,000 people by the end of that year.While he is not the highest-ranking U.S. official to have toured the museum and memorial park, a distinction that belongs to then-U.S. Speaker of the House of Representatives Nancy Pelosi in 2008, Kerry is the most senior executive branch official to visit.