Washington, US: The United States is pressing Cuba to allow the opening of its embassy in Havana by April, US officials told Reuters, despite the Communist island's demand that it first be removed from the U.S. list of state sponsors of terrorism.

A refusal by Cuba to allow the United States to quickly establish an official embassy for the first time in half a century could complicate talks between the Cold War foes, reflecting enduring mistrust as they move to end decades of confrontation.

Striking Cuba from the terrorism list could take until June or longer, although the White House is pushing officials to move quickly, said two US officials with direct knowledge of the State Department's review to take Cuba off the list.

Washington is eager to re-establish diplomatic ties before a regional summit in Panama in April, when President Barack Obama will meet Cuban leader Raul Castro for the first time since 2013, the officials said.

A historic deal

The two leaders announced a historic deal on 17 December to restore relations. US and Cuban diplomats will meet this month or in early March in Washington for a second round of talks.

While renewing diplomatic relations could happen quickly, the process to normalize, including removing the U.S. trade embargo, will take far longer.

Cuba has not made removal from the list a condition for restoring ties, US officials said. But Havana made clear during the first round of talks last month that it first wants to be removed from the terrorism list.

Getting the embassy open is tricky

Converting the six-story US interests sections in Havana into a full-fledged embassy after 53 years would require ending restrictions on the number of US personnel in Havana, limits on diplomats' movements and appointing an ambassador. It would allow the US to renovate the building and have US security posted around the building, replacing Cuban police.

Cuba also wants the United States to scale back its support for Cuban dissidents when the sides meet again. US administration officials have stood firm both publicly and privately that they intend to keep supporting the dissidents.