WASHINGTON — The Obama administration on Friday removed Cuba from a list of state sponsors of terrorism, a crucial step in President Obama’s push to normalize ties between Washington and Havana.

Secretary of State John Kerry rescinded Cuba’s designation at the end of a 45-day congressional notification period, which began on April 14 when Mr. Obama announced his intention to remove Cuba from the list.

“While the United States has significant concerns and disagreements with a wide range of Cuba’s policies and actions, these fall outside the criteria relevant to the rescission of a state sponsor of terrorism designation,” Jeff Rathke, the State Department spokesman, said in a statement.

The action came amid signs of difficulty in the negotiations between American and Cuban officials to carry out the historic reopening that Mr. Obama announced in December. Despite widespread optimism, officials failed in talks last week to reach an accord on re-establishing diplomatic relations and opening embassies.