Bilateral talks between Japan and North Korea ended their second day with no agreement made on the dispute over the abduction of Japanese citizens.
Some relatives believe their loved ones are still alive in the North
Significant differences remain, said Pyongyang, on the abductions by North Korean agents in the 1970s and 1980s.
Japan sees this issue as crucial to reopening of diplomatic relations.
The Beijing talks - part of the first high-level contact between the two in three years in the hope of normalising relations - continue on Monday.
The two nations are also likely to use the talks to discuss possible reparations for Japan's colonial rule in North Korea, as well as Pyongyang's nuclear ambitions.
Envoys from North Korea and Japan spent Sunday in a hotel in the Chinese capital.
Speaking of the abduction issue, North Korea's delegate Kim Chol Ho told reporters: "There are big differences of opinion and stance on the issue."
"We also told (Japan) how much sincerity and effort we've put into resolving the issue and we both agreed to continue to talk," he said.
In a separate briefing, after more than nine hours of discussions Japan's envoy, Kunio Umeda, said the two sides traded views on the abductions.
Japan "conveyed in a specific manner" its demands for the return of any surviving abductees, as well as the handover of North Korean agents involved in their disappearances, he told reporters.
"We repeated that resolution of the abduction issue is very important to normalising diplomatic relations," said the Japanese envoy.
Snatched in the '70s and '80s
Used as cultural trainers for N Korean spies
Five allowed home in 2002
Five children now freed from N Korea
Eight said to be dead, others missing
"We'll urge Pyongyang to deal with the abduction issue sincerely by returning abductees, unveiling the truth and handing over suspects."
North Korea has admitted kidnapping 13 Japanese to train as spies, and has already repatriated five of those kidnapped, saying the eight others are dead.
But Tokyo says Pyongyang has never provided conclusive proof of their deaths, and many Japanese suspect some of them may still be alive.
Mr Umeda and Mr Kim said the two sides discussed whether those involved in the kidnappings would be brought to justice but no resolution was made.
"This is something we have to talk more about," North Korea's Kim Chol Ho said. said.
The bilateral discussions are the second in little over a month, after they resumed following a one-year gap.
In the last negotiations, in November, the two sides made little progress, with the North demanding compensation for Japanese occupation during the first half of the 20th Century, and Tokyo continuing to ask questions about the abduction issue.
Japan has repeatedly offered financial aid to North Korea, but says the offer is only available after diplomatic relations are established.
Japan gave South Korea $500m when Tokyo and Seoul normalised ties in 1965.