North Korea has returned its staff to an inter-Korean liaison office, Seoul said on Monday, just days after unilaterally withdrawing from the joint facility.
The office in the northern city of Kaesong was opened in September as the two Koreas knitted closer ties, but the North pulled its staff out last week amid a deadlock in talks between Washington and Pyongyang.
The unification ministry said some of the North Korean staff were back at work, saying they had come to cover their "shift as usual".
"Thus, the South and the North held consultation at the liaison office this morning and will continue to operate the office as usual," the ministry said.
It said the North did not offer details on why it had returned or pulled out in the first place.
South Korean President Moon Jae-in was instrumental in brokering the talks process between the nuclear-armed, sanctions-hit North and the US, Seoul's key security ally.
Mr Moon has long backed engagement with the North to bring it to the negotiating table, and has been pushing the carrot of inter-Korean development projects, among them an industrial zone also in Kaesong and cross-border tourism for South Koreans.
But the failure by North Korean leader Kim Jong -un and US President Donald Trump to reach agreement in Hanoi last month on walking back Pyongyang's nuclear programme in exchange for relaxation of the measures against it has raised questions over the future of the process.
In his New Year speech – a key political event in the North – Mr Kim said without giving details that Pyongyang might encounter a "new way for defending the sovereignty of the country and the supreme interests of the state" if Washington persisted with sanctions.
