Prime Minister Shinzo Abe has explained his government's drastic monetary measures to German Chancellor Angela Merkel, who voiced concern about the unorthodox policy earlier in the week, government officials said.

Abe's remarks during the 20-minute phone call Friday were aimed at reassuring Berlin after the Bank of Japan announced a 2 percent inflation target and plans for unlimited monetary easing on Tuesday.

Speaking at the World Economic Forum in the Swiss resort of Davos, Merkel expressed caution Thursday about Tokyo's aggressive easing stance and the amount of pressure the BOJ came under from Abe's administration. Two leading German financial officials last week also criticized the policy, arguing that it risks putting German exporters at a disadvantage by excessively weakening the yen against the euro.

During Friday's phone call, Merkel offered her condolences for the deaths of 10 Japanese last week during the hostage crisis in Algeria. Abe said that the international community needs to stand together in the fight against terrorism.

Meanwhile, the two leaders agreed on the need for stronger global cooperation to prevent North Korea from advancing its nuclear capabilities, following Pyongyang's vow to stage a "high level nuclear test" in the near future. They also confirmed their continued cooperation on resolving the abduction of Japanese nationals by the North's agents in the 1970s and 80s.