The claim asserts that a U.S. official stated Secretary of State Marco Rubio was not part of the delegation. This specific denial is only found within the context of the provided web search results and is not corroborated by a second, independent news source reporting the same fact. While Marco Rubio is mentioned in relation to the State Department in the evidence, the specific denial regarding his absence from the delegation is limited to the source context.

The claim combines multiple elements: (1) an American delegation meeting Cuban officials, (2) a renewed diplomatic push, (3) Trump threatening intervention, and (4) Cuba's leader warning of fighting. While the web search results mention a State Department official meeting with the grandson of Raúl Castro and a delegation visiting Cuba amid pressure from the Trump administration, the specific combination of all these elements—especially the direct quote about Cuba's leader warning of fighting in this context—is not corroborated by multiple independent sources. The evidence points to a recent meeting and diplomatic opening, but the full context of the threat/warning is limited to the provided search snippets.

The claim states that a senior State Department official met with Raúl Guillermo Rodríguez Castro last week. This specific detail is reported in multiple web search results, indicating it is a key piece of information from the original reporting. However, the evidence provided does not contain enough independent, diverse sources (like multiple news organizations reporting the same event) to elevate the verdict beyond 'single_source' based on the strict criteria, although the information is consistently present across the search results.