US Secretary of State Hillary Rodham Clinton condemned North Korea today for the sinking of a South Korean warship in March, which resulted in the death of 46 sailors, according to dpa. "The United States strongly condemns this act of aggression" by North Korea, said Clinton, who briefly stopped by Tokyo at the start of an Asian tour. "I think it is important to send a clear message to North Korea that provocative actions have consequences. We cannot allow this attack on South Korea to go unanswered by the international community." The South Korean warship sank on March 26 in confusing circumstances. After talks with Clinton, Japanese Foreign Minister Katsuya Okada told a joint news conference that he and Clinton had agreed that it was important for Japan, the US and South Korea to work closely to deal with the incident. Their meeting came one day after a multinational team of investigators found Pyongyang responsible for the sinking of the warship. "We'll be in deep and constant consultations, not only between the United States and Japan, but also with South Korea, China and others to determine our response," Clinton said. Clinton and Okada also agreed that the US and Japan would work together to try to settle by the end of May the issue of where to relocate a US Marine Corps base on the Japanese island of Okinawa. The end of May is Japanese Prime Minister Yukio Hatoyama's self- imposed deadline. Hatoyama told reporters after meeting Clinton separately that it was productive for the two countries to reconfirm the significance of their long-standing alliance amid mounting tensions in North-east Asia. "We agreed that this year is going to be the time to deepen the US-Japan alliance," the premier said. After her brief stop in Tokyo, Clinton was to visit the World Expo in Shanghai, and then go to Beijing to attend the US-China Strategic Economic Dialogue with US Treasury Secretary Timothy Geithner on Monday and Tuesday. On Wednesday, Clinton will fly to South Korea to meet with President Lee Myung-bak and Foreign Minister Yu Myung Hwan.