The historic process of restoring long-severed diplomatic relationships between the U.S. and Cuba that began Dec. 17 will likely come to a successful end in a matter of weeks, a U.S. senator said during a visit to the island.

A 45-day period for Congress to challenge a decision by President Barack Obama to remove Cuba from a list of state sponsors of terrorism, a key obstacle to improved relations, will expire Friday and the remaining issues will then get quickly resolved, Sen. Tom Udall told reporters in Havana Wednesday.