UNITED NATIONS - UN Secretary-General Ban Ki-moon is deeply alarmed at the rising tensions on the Korean peninsula, though United Nations humanitarian workers remain active across North Korea for the time being, a spokesman said on Friday."UN staff in the DPRK (North Korea) remain engaged in their humanitarian and developmental work throughout the country," UN spokesman Martin Nesirky said in a conference broadcast in New York. "The secretary-general remains deeply concerned about escalating tensions on the Korean peninsula." Nesirky said that UN officials were present at a meeting on Friday in Pyongyang along with other foreign diplomats at which North Korean officials asked embassies to consider moving staff out and warned their safety cannot be guarantee after April 10."The United Nations is studying the message and the United Nations will respond as appropriate," he said.The North Korean message comes on the heels of declarations by the government of the secretive communist state that conflict is inevitable because of what it terms "hostile" US troop exercises with South Korea and UN sanctions imposed over North Korea's nuclear weapons testing."There is a general need for things to calm down, for the volume to be turned down," Nesirky said."It is really incumbent on the DPRK authorities to reduce the tension," he said. "It is after all the DPRK authorities that have made a number of statements in the recent days and indeed weeks that the secretary-general and others have said are alarming." North Koreans suffer from chronic poverty and widespread hunger, UN officials say.