Bilateral talks are on the table as Tokyo seeks to salve the running sore of abductions of its nationals by North Korean spies in the 1970s and 1980s, an issue that inflames public opinion at home.
But any move to break with Washington and Seoul, who have both stressed the need for a united approach to Pyongyang, could rankle.
"As we are seeking all possibilities, of course such a thing is an option," Chief Cabinet Secretary Yoshihide Suga told reporters when asked about resuming talks suspended last year when North Korean announced a rocket launch.
Iijima told North Korean officials that Tokyo "would not make any move" unless they return all Japanese kidnap victims, hand over the kidnappers and resolve all the abduction cases, according to Japanese media citing sources close to him.
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The trip fuelled speculation Pyongyang was trying to cozy up to Tokyo at a time when ties with Washington and Seoul have gone into deep freeze over its nuclear and missile ambitions.
Glyn Davies, the US special representative for North Korea policy, cautioned that Pyongyang was trying to "split" the international community.
Washington would like to see the resumption of six-party talks, which involve the two Koreas, the US, Japan, China and Russia, and are intended to denuclearise the Korean peninsula.
Abe has set great store by seeking a "comprehensive solution" to the abduction issue, along with Pyongyang's nuclear and missile ambitions.
Iijima was a senior aide to Junichiro Koizumi and accompanied his visits to Pyongyang in 2002 and 2004 as Japan's prime minister for talks with then-North Korean leader Kim Jong-Il.
Several of those snatched were allowed to return to Japan along with children who were born in the North, but Pyongyang said the rest of them had died, although many in Japan were not convinced.