Japan has been facing growing calls internally for overhauling its policy toward North Korea, by allowing talks on possible economic aid to precede the delayed effort to resolve the issue of past abductions of Japanese by Pyongyang, government sources said Friday.

While North Korea has shown no signs of backing down from claiming that the issue of abductions in the 1970s and 1980s has been settled, Japan has maintained it will not normalize diplomatic relations with the North and extend economic assistance unless the issue is resolved.

The proposed policy, which still faces strong opposition in the government, would focus on building mutual trust before paving the way for the resolution of the abduction issue, the sources said.

Since returning to power in 2012, Prime Minister Shinzo Abe has placed priority on resolving the issue, and recently expressed his desire to engage in direct talks with North Korea.

The government is expected to decide how to approach North Korea, depending on progress in the ongoing talks between the United States and North Korea on denuclearization of the North, the sources said.

A series of meetings have been held at the prime minister's office since April to discuss Tokyo's strategy to get Pyongyang to the negotiating table. But no decision has been made so far.

(U.S. Ambassador to Japan William Hagerty, 2nd from left, listens to Sakie Yokota, right, the mother of Megumi Yokota who was abducted to North Korea when she was 13, at his official residence in Tokyo)

The sources said one of the participants argued over the course of the meetings that Japan needs to foster ties with North Korea through talks on economic cooperation. Infrastructure building and natural resource development are seen as potential areas of such cooperation.

But opponents have said such an approach would call into question the seriousness of the Abe administration that had placed its "highest priority" on the abduction issue, the sources said.

The brainstorming comes at a time when expectations are growing for major progress in North Korea's denuclearization after U.S. President Donald Trump met with the North's leader Kim Jong Un in the Singapore summit in June.

Washington has told Pyongyang during bilateral talks that its denuclearization will pave the way for Tokyo to extend economic assistance, the sources said.

The Japanese government officially lists 17 people as having been abducted by the North. Five of them returned in 2002, but Pyongyang maintains eight have died and four others never entered the country.

In the past, Japan changed its negotiating tactics but the shift did not result in a major breakthrough.

Tokyo proposed to Pyongyang during talks in November 2005 that they discuss multiple issues in parallel and set up subcommittees tasked with Pyongyang's abductions, security and the normalization of ties.