HAVANA (AFP) - US and Cuban officials welcomed the first day of their historic diplomatic talks in Havana on Wednesday as "productive" and "constructive" despite lingering differences over migration issus.

The first of two days of talks aimed at ending decades of Cold War enmity focused on migration.

The two sides remained at odds over a US policy that gives Cubans who set foot in the United States quick access to permanent residency, but the two delegations said they had made progress.

"The productive and collaborative nature of today's discussion proves that despite the clear differences that remain between our countries, the United States and Cuba can find opportunities to advance our mutually shared interests, as well as well as engage in a respectful and thoughtful dialogue," US deputy assistant secretary of state Alex Lee told reporters.

The Cuban foreign ministry's director of US affairs, Josefina Vidal, said the discussion was held in a "respectful and constructive atmosphere."

But she reiterated Cuba's opposition to the US "wet foot, dry foot" policy, in which only Cubans caught at sea are deported back home.

The second day of talks will centre on the work needed to reopen embassies and return ambassadors for the first time since relations broke in 1961.

Roberta Jacobson, the US assistant secretary of state for Western Hemisphere affairs, landed in Havana around midday to participate in Thursday's talks.