PARIS (Reuters) - France s Emmanuel Macron discussed increased pressure and sanctions on North Korea on the telephone with U.S. President Donald Trump and Japan s Prime Minister Shinzo Abe on Saturday, the French president s office said. The three leaders stressed the need for a  united and firm  reaction from the international community toward Pyongyang, Macron s office said. South Korea was bracing on Saturday for a possible further missile test by North Korea as it marked its founding anniversary, just days after its sixth and largest nuclear test. The French presidency said North Korea s  repeated provocations  were a  threat to peace and international security . It also said Macron had expressed France s  solidarity  with Japan. Tension on the Korean peninsula has escalated as North Korea s leader, Kim Jong Un, has stepped up the development of weapons, testing a string of missiles this year, including one flying over Japan. Experts believe the Pyongyang government is close to its goal of developing a powerful nuclear weapon capable of reaching the United States, something U.S. President Trump has vowed to prevent. 