Japan today decided to tighten financial sanctions against North Korea over the deadly sinking of a South Korean warship in March. <br/><br/>Chief government spokesman Hirofumi Hirano said the cabinet decided to lower the cap at which people in Japan will have to report remittances to North Korea from more than 10 million yen to three million yen. <br/><br/>The stepped up sanctions came after Prime Minister Yukio Hatoyama and US President Barack Obama spoke on the phone about North Korea. <br/><br/>Hirano told a regular press conference the prime minister and President Obama agreed that North Korea's conduct is unforgivable and that Japan and the United States will cooperate on the issue. <br/><br/>Japan has in the past imposed a trade ban on North Korea and denied visas to its citizens to punish the communist state for its nuclear and missile programmes and the past kidnappings of Japanese nationals.