Currently, families must travel by air to visit relatives separated by decades of fighting in the desert region.
"In concluding this fourth round of talks, the parties reiterated their commitment to continue the negotiations at Manhasset at a date to be determined by common agreement," Peter van Walsum, the UN special envoy for Western Sahara, said in a statement on Tuesday.
'In good faith'
Van Walsum, who mediated the two-day talks in the secluded Greentree estate in the New York suburb of Manhasset, said they focused on implementation of UN Security Council resolutions urging talks "without pre-conditions and in good faith" to achieve "a just, lasting and mutually acceptable political solution".
He said the parties also addressed issues such as administration, justice and resources in the former Spanish colony, which Morocco annexed in 1975 following the withdrawal of colonial power Spain, sparking a war with the Polisario.
"Among a number of proposals I made to expand confidence-building measures, there was agreement among the parties to explore the establishment of family visits by land, which would be in addition to the existing programme by air," van Walsum said.
That represented a slight advance in a series of talks to resolve the 32-year dispute for control of the Western Sahara that have ended in stalemate, but no progress on fundamental claims of land ownership.
The UN-mediated talks, which followed earlier rounds in January as well as in June and August last year, brought together Morocco, the Algiers-backed Polisario as well as representatives of neighbouring Algeria and Mauritania.
Morocco has offered broad autonomy to Western Sahara, a mainly desert territory in north-west Africa, but the Polisario Front is seeking a referendum with the option of full independence.
On the eve of the fourth round of talks, Chakib Benmoussa, the Moroccan interior minister, made it clear that Rabat "only accepts autonomy and nothing but autonomy" for the Western Sahara.
Benmoussa blamed the continuing impasse on the Polisario Front's "rigid, outdated positions".
He said that Rabat remains committed to negotiations with the aim of reaching "a political solution that guarantees the return of all Saharawis to their motherland, Morocco".
Ahmed Boukhari, a Polisario representative, said that "there was no substantial progress unfortunately" because of Morocco's "rejection to the implementation to the right of self-determination".
Both sides said they looked to the Security Council to heighten pressure for a solution.