Australian Prime Minister Scott Morrison, left, is welcomed by Japanese Prime Minister Shinzo Abe upon his arrival for a welcome and family photo session at G20 leaders summit in Osaka, Japan, Friday, June 28, 2019. (Kim Kyung-Hoon/Pool Photo via AP)

CANBERRA, Australia (AP) — Australia's prime minister said he discussed the disappearance of an Australian student in North Korea with other world leaders attending the Group of 20 summit and accepted offers to find out what happened to him.

Prime Minister Scott Morrison said the plight of Alek Sigley had been raised with him by world leaders attending the meetings in Osaka, Japan, including Japanese Prime Minister Shinzo Abe.

Morrison, who dined with President Donald Trump on Thursday night, declined to say which government leaders he had discussed the disappearance with and what help had been offered. He said he did not discuss the 29-year-old student with the leader with the most influence over North Korea, Chinese President Xi Jinping.

"In the short time we had available, I didn't have that opportunity, but I discussed it with many other leaders," Morrison told reporters in Osaka on after his meeting with Xi on Friday.

"I have had the issue ... raised with me last night and today by other leaders and I've raised it with them as well — those who particularly have insights and abilities to assist us — and those offers of assistance have been very genuine, but I must say our key focus at the moment is to ascertain precisely where Alek is and in what circumstances and that's the focus of the efforts of our officials and our partners right now," he added.

Australia has diplomatic ties with North Korea but does not have an embassy there. The Swedish Embassy in Pyongyang offers limited consular help to Australians.

Sigley, a Pyongyang university student and tour guide, has been out of contact since Tuesday and some media reports say he was detained. Official media in North Korea haven't mentioned an arrest.

His Japanese wife Yuka Morinaga, 26, said she usually speaks to him daily by WhatsApp from her home in Tokyo, but had not heard from him since Monday.

Morinaga, a software developer who married Sigley in a lavish ceremony in Pyongyang last year, told News Corp. she was "very concerned."

"We don't know what's happened," Morinaga said. "We don't even know if he's been detained or not."

"Some people might say he's naive because he's very pure and believes in ... doing good," she added.

Sigley's family said on Friday they had shuttered his social media accounts "to limit unnecessary speculation and commentary on those channels." The closures block the public from making potentially unhelpful posts to his accounts.

"He remains out of digital contact with friends and family, and Australia's Department of Foreign Affairs and Trade continues to seek clarification as to his whereabouts and welfare," a family statement said.

"Alek's family and friends hope to hear from him soon," the family added.

Australia advises people to reconsider their need to travel to North Korea due to how its laws apply to foreigners and says foreign visitors have been subject to arbitrary arrests and long-term detentions.

North Korea has been accused in the past of detaining Westerners for slight infractions and using foreign detainees as political pawns to gain concessions. As the country pursued diplomacy with the United States last year, it released three American detainees in what the nation's propaganda described as a gesture of goodwill.

Leonid Petrov, an Australian National University expert on North Korea and friend of Sigley, suspected that the missing Australian had been "deliberately cut off from means of communications" temporarily because Trump was in the region.

"I know Alek well and he has been always on Facebook, on Skype and he is very proactive in the media," Petrov said.

"In the context of what is going on on the Korean Peninsula right now — President Trump is in Japan today, going to be in South Korea on Sunday, potentially going to the Demilitarized Zone — I believe tensions and security measures are heightened both in South and North Korea," he said.

"I think that North Koreans potentially might have decided to shut down his blog, his Facebook account because the information coming out of North Korea ... is unprecedented. Normally North Korea is a closed book," he added.

This undated photo provided by the Sigley family shows Alek Sigley. Australian Prime Minister Scott Morrison said on Friday, June 28, 2019, in Osaka, Japan, that he remained concerned for the Australian student who is uncontactable in North Korea and has been offered international support to find him. Morrison said the plight of Alek Sigley had been raised with him by world leaders attending the Group of 20 summit in Osaka including Japanese Prime Minister Shinzo Abe. (Courtesy of the Sigley family via AP)
In this image made from video, Australian Prime Minister Scott Morrison speaks in Osaka, western Japan, Friday, June 28, 2019. Morrison said he remained concerned for an Australian student who is uncontactable in North Korea and has been offered international support to find him. Morrison said the plight of Alek Sigley had been raised with him by world leaders attending the Group of 20 summit in Osaka, including Japanese Prime Minister Shinzo Abe. (Australian Broadcasting Corporation via AP)
Australian Prime Minister Scott Morrison, left, is welcomed by Japanese Prime Minister Shinzo Abe upon his arrival for a welcome and family photo session at G-20 leaders summit in Osaka, Japan, Friday, June 28, 2019. (Kim Kyung-Hoon/Pool Photo via AP)
Australian Prime Minister Scott Morrison, from left, German Chancellor Angela Merkel, Canadian Prime Minister Justin Trudeau and French President Emmanuel Macron speak before a plenary session at the G20 Summit in Osaka, Japan, on Friday June 28, 2019. (Adrian Wyld/The Canadian Press via AP)
White House senior advisor Ivanka Trump, left, attends a dinner with her father President Donald Trump and Australian Prime Minister Scott Morrison in Osaka, Japan, Thursday, June 27, 2019. President Donald Trump and Morrison are in Osaka to attend the G20 summit. (AP Photo/Susan Walsh)
President Donald Trump, third from left, attends dinner with Australian Prime Minister Scott Morrison, third from right, in Osaka, Japan, Thursday, June 27, 2019. Trump and Morrison are in Osaka to attend the G20 summit. (AP Photo/Susan Walsh)