The suspension came with inter-Korean ties at a standstill, despite three summits between the North's Kim Jong Un and the South's President Moon Jae in 2018
North and South Korea signalled a surprise thaw in relations on Tuesday, announcing a restoration of cross-border communications that were severed more than a year ago and revealing that their leaders had exchanged a series of letters.
The North unilaterally cut off all official military and political communication links in June last year after threats over activists sending anti-Pyongyang leaflets across the border.
The suspension came with inter-Korean ties at a standstill, despite three summits between the North's Kim Jong Un and the South's President Moon Jae in 2018.
But the two sides said all communication lines were restored on Tuesday.
"According to the agreement made between the top leaders, the north and the south took a measure to re-operate all inter-Korean communication liaison lines from 10am Tuesday (0100 GMT)," North Korea's official KCNA news agency reported.
Kim and Moon have exchanged personal letters since April aimed at improving ties, the South Korean president's office said in a statement, and agreed to restore the hotlines as the first step.
"The two leaders also agreed to restore mutual trust between the two Koreas as soon as possible and move forward with the relationship again."
The dovish Moon is credited with brokering the first-ever summit between North Korea and a sitting US president in Singapore in June 2018.
But Pyongyang largely cut off contact with Seoul following the collapse of a second summit between Kim and then US president Donald Trump in Hanoi that left nuclear talks at a standstill.
'Kim's first response'
Since President Joe Biden took office, Pyongyang and Washington have adopted a wait-and-see attitude to relations following the diplomatic roller coaster ride under Trump that produced three summits but no agreement on dismantling the North's nuclear arsenal.
Kim said in June that Pyongyang needed to prepare for both "dialogue and confrontation" with Washington – but with a particular emphasis on the latter.
The White House promised a "practical, calibrated approach" – including diplomatic efforts – in a recent review of its strategy to persuade the impoverished North to give up its nuclear weapons and missile programs.
Sung Kim, the top US diplomat in charge of North Korea negotiations, said in June that Washington was ready to meet with Pyongyang "anywhere, anytime, without preconditions."
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But Kim Yo Jong – Kim Jong Un's sister and a key adviser – dismissed the offer.
Analysts said Tuesday's restoration of the inter-Korean hotlines signalled Kim's initial response to Washington's talks offer.
"It looks like he has decided that restoring inter-Korean relations is beneficial to the North's both domestic and foreign policies and politics," Yang Moo-jin, a professor at the University of North Korean Studies, told AFP.
Despite the standstill in talks, Moon has relentlessly stressed the importance of restoring inter-Korean ties, he added.
"This should be read as Kim Jong Un's first response to Seoul and Washington," Yang said.