The Liberal Democratic Party on Wednesday condemned North Korea for its recent spate of missile launches.
"We strongly denounce (the missile launches) as violating U.N. resolutions, and posing a grave challenge to the international community," the LDP said in a statement by its committees on diplomacy, security and defense.
"North Korea forced through the launches without prior notice to countries concerned and put aircraft and ships in great danger. We simply cannot accept that," the statement said.
It went on to urge the government to coordinate efforts with Washington to take "all necessary steps" against North Korea.
The statement was issued days after Japan and North Korea held informal talks in China on the sidelines of a meeting between their Red Cross societies, raising hope for breaking the diplomatic impasse.
A senior Foreign Ministry official told an LDP meeting Wednesday that Japan brought up the missile launches during the talks.
"We expressed our views on various challenges facing Japan and North Korea. They inevitably include the missile launches (early Monday)," said Junichi Ihara, director general of the Foreign Ministry's Asian and Oceanian Affairs Bureau.
Ihara also said Japan will strive to realize formal bilateral negotiations that have been stalled since November 2012 by "seizing on every opportunity."
Details of the informal talks in China are not yet known, but Japan is believed to have raised the abductions of Japanese by North Korea in the 1970s and 1980s, as Prime Minister Shinzo Abe has pledged to resolve this issue while he is in office.
North Korea launched two short-range missiles Monday and seven rocket-propelled projectiles Tuesday.
All were fired from its eastern coast. It is believed that North Korea was responding to a U.S.-South Korean military exercise. Tokyo lodged a protest with Pyongyang over Monday's launches.