MIAMI, United States (AFP) — United States (US) Secretary of State Marco Rubio said Thursday that Cuba accepted an offer of US$100 million in aid but that it was unclear if Washington would agree to Havana’s terms.

Cuba has publicly only said that it was reviewing the offer made by Rubio and tensions have risen after the United States on Wednesday indicted the country’s influential former president Raul Castro on murder charges.

“They say they’ve accepted it. We’ll see if that means it” will work out, Rubio told reporters in his home city of Miami as he left for a NATO meeting in Sweden.

“We’re not going to do humanitarian aid that falls into the hands of their military company that they have. And then they take that stuff and they sell it at the dollar stores and put the money in their pocket,” Rubio said.

Rubio, a Cuban-American and vociferous critic of the communist government in Havana, said that the United States was hoping to avoid the use of force.

The indictment in Miami of the 94-year-old former president over a 1996 downing of two aircraft raised speculation that President Donald Trump could use the charges as a pretext to attack the island and seize him.

“The president always has the option to do whatever it takes to support and protect the national interest and national security of the United States,” Rubio said.

“That said, our preference is always a diplomatic solution,” he said.

But Rubio also made clear he believed Cuba posed a threat.

“Cuba not only has weapons that they’ve acquired from Russia and China over the years, but they also host (a) Russia and Chinese intelligence presence in their country, not far from where we’re standing right now,” he said.

“So Cuba has always posed a national security threat to the United States.”