The talks are expected to focus on an amended version of a seven-day proposal that Iran presented last week on the sidelines of the United Nations General Assembly, said an official who spoke on condition of anonymity.
Araqchi remains in New York after attending the General Assembly.
It was not immediately clear who would represent the US side in the talks with mediators.
The Iranian ISNA news agency later confirmed that Araqchi would meet the mediators in the US on Monday morning, New York time.
The two sides will "examine the latest proposals and views regarding the current situation," ISNA added.
Iran's foreign ministry spokesman Esmaeil Baghaei told state media later on Monday that Araqchi's stay in New York had not been extended and that the foreign minister would return to Tehran according to his original schedule.
Baghaei made no comment on the talks with mediators.
Iran's seven-day plan envisages an end to all hostilities in Iran and Lebanon, the unfreezing of billions of dollars' worth of Iranian assets, an end to sanctions on Iranian oil and the lifting of the US blockade on Iranian ports.
Iran would then allow the reopening of the Strait of Hormuz and the two sides would also resume talks on Iran's nuclear program.
US President Donald Trump said on Saturday he had rejected the Iranian proposal, saying Iran wanted a swift agreement because of the crippling economic pressure it is under.
However, he also told Axios on Sunday that he expected US negotiators to engage in further talks this week.
Araqchi said on Sunday that mediators had not formally conveyed a US rejection to Iran and that it was awaiting a definitive position from the US before deciding its next steps.
"Our conditions are clear, and any move toward reopening the Strait of Hormuz is contingent on these conditions being met," he said on Sunday, adding that only a negotiated solution could resolve the impasse.
