Jordan may be willing to free a convicted suicide bomber in return for the release of a Japanese journalist and a Jordanian pilot being held by Islamic State (Isis), a Japanese news agency has reported.

The claim, made in a Kyodo News interview with two members of the Jordanian parliament, raises hopes that Kenji Goto, a freelance journalist who has been under threat of execution by the Islamist terrorist group for almost a week, will be the beneficiary of a prisoner swap, despite opposition from the US.

Japan’s envoy in the region, the deputy foreign minister, Yasuhide Nakayama, gave further cause for guarded optimism when he said he hoped Goto and his fellow captive, First Lt Muath al-Kaseasbeh, would return home “with a smile on their faces”.

Tokyo has refused to give details of continuing discussions with Jordanian authorities, with the prime minister, Shinzo Abe, repeating his refusal to bow to demands from terrorists.

Abe, who has publicly allied Japan with the campaign against Isis, is under mounting pressure to secure the release of Goto following the execution of his friend and fellow hostage, Haruna Yukawa, at the weekend.

Yukawa, 42, was reportedly beheaded after Japan failed to meet a Friday deadline for payment of a $200m (£132m) ransom demanded by Isis for Yukawa and Goto.

In a message purportedly read out by Goto after Yukawa’s death, Isis said it was demanding the release of Sajida al-Rishawi, an Iraqi who is on death row in Jordan for her involvement in a 2005 suicide bombing that killed 60 people.

In what could be a decisive development, Kyodo quoted Bassam al-Manaseer, who chairs the Jordanian parliament’s Arab and international affairs committee, and Ali Bani Ata, chair of the Japan-Jordan parliamentary friendship league, as saying that Jordanian authorities “may comply” with Isis’s demand for Rishawi’s release.

The officials said Jordan had been in contact with Isis through a third party, according to the news agency’s report from the capital, Amman.

Jordan’s King Abdullah was quoted as telling a Jordanian newspaper that the case of the pilot “tops the country’s priorities”.

Japan’s government spokesman, Yoshihide Suga, told reporters he was not aware of any progress towards a possible prisoner swap involving Goto and Kaseasbeh.

Manaseer said it was highly unlikely that Jordan would release Rishawi in return for Goto alone, since that would leave the Jordanian hostage in Isis hands with the hostage swap already complete, Kyodo said.

Any deal between Jordan and Isis would anger the US, which opposes prisoner swaps and paying ransoms to terrorist groups. Jen Psaki, a US state department spokeswoman, told journalists in Washington that trading captives belonged “in the same category” as paying ransoms.

She said last year’s release of five Taliban commanders in return for captive US army sergeant Bowe Bergdahl was “entirely different” since Bergdahl was being held as a prisoner of war.

Citing firm ties between Japan and Jordan, Nakayama said both countries were determined to bring the men home. “I hope we can all firmly work hard and join hands to cooperate, and for the two countries to cooperate, in order for us to see the day when the Jordanian pilot and our Japanese national, Mr Goto, can both safely return to their own countries with a smile on their faces,” he told reporters in Amman.

Isis has been holding Kaseasbeh since his aircraft crashed during a US-led bombing raid over eastern Syria in December.

The faint possibility of Goto’s release came as Abe fended off criticism of his handling of the hostage crisis, the first involving Japanese citizens at the hands of Isis. On Tuesday, an opposition MP asked Abe why he explicitly referred to Isis when announcing $200m in non-military aid to countries involved in the fight against the terrorist group earlier this month.

Abe replied: “If we fear the risks so much that we succumb to the terrorists’ threats, we won’t be able to make any humanitarian contributions to countries surrounding the area of conflict.

“Our country will never bow to terrorists. We will continue to provide humanitarian support in our own way.”