In a surprise announcement, North and South Korea said separately Tuesday that they had restored previously severed cross-border communications, a move that could bolster prospects for stalled nuclear diplomacy.

The development comes more than a year after Pyongyang blew up ties — and an inter-Korean building that had been symbolic of the relationship. The two sides also chose an auspicious date for the announcement: the 68th anniversary of the truce that halted the Korean War.

The two Koreas, which technically remain in a state of war, said that the decision to restore links had come after a series of personal letters were exchanged by South Korean President Moon Jae-in and North Korean leader Kim Jong Un starting in April in an attempt to shore up ties.