JAKARTA - Indonesia has demanded that the United States explain why Indonesian armed forces chief, General Gatot Nurmantyo, was blocked from travelling to Washington D.C. on Saturday (Oct 21), said Foreign Minister Retno Marsudi.

"For us there are two different issues, one is to resolve that the ban no longer exists, but the second is that we are still asking for a clarification, an explanation, on why did the incident happen?" said Ms Retno.

The Indonesian minister was speaking to reporters on Monday after meeting with US Deputy Ambassador to Indonesia, Ms Erin Elizabeth McKee, who was summoned to the foreign ministry in Jakarta earlier in the morning.

Ms McKee, representing US Ambassador Joseph Donovan who was away, had expressed regret for the treatment of General Gatot, who was told he cannot travel to the US despite having been invited to Washington by General Joseph Dunford, chairman of the US Joint Chiefs of Staff.

"We deeply regret the inconvenience that this incident caused and we apologise," said Ms McKee. "We have resolved the matter, General Gatot is able to travel, there are no restrictions and the United States welcomes his participation in the conference that General Dunford had invited him to."

She also added that the US embassy is "working very hard to understand what transpired in this incident and we hope that it will not happen again".

Ms Retno said the US ambassador had apologised for the incident in a phone call on Sunday, and reiterated the importance of Indonesia's relationship with the US.

The American embassy in Jakarta also posted a statement on its website on Sunday, apologising for the inconvenience caused to the general, adding that it was working to facilitate his travel.

The US statement came after Indonesia sent a diplomatic note to the US Secretary of State over the weekend and summoned the US ambassador to explain the incident.

General Gatot, who is due to retire from the military in March next year, is a popular but sometimes controversial public figure in Indonesia.

Last month, he made it compulsory for troops to watch an anti-communist propaganda film made during the Suharto-era, a move critics said could revive a 'Red Scare" in Indonesia.

He has also held a longstanding belief that Indonesia faces "proxy wars", where foreign states seek to undermine his country by manipulating non-state actors.

The US apologies did not seem to placate supporters of the general, whom many had touted to have political ambitions.

By Monday afternoon, banners were spotted in downtown Jakarta that said "Expel the US Ambassador". But they were removed later in the day by city officials.

Ms Retno said that Jakarta is now waiting for her counterpart in the US to investigate the incident, in a bid to offer an explanation as to why its top military commander was denied entry.