Cuba announced Tuesday it would defend itself in US court against oil giant ExxonMobil, which has accused two companies on the island nation of "unlawful trafficking" of its assets after Fidel Castro's 1959 communist revolution.

The US giant filed a suit in May in a Washington federal court seeking $280 million from state-owned oil company Cuba-Petroleo (Cupet) and Cimex, which operates service stations on the island.

State television in Cuba said the two companies had "taken formal steps, through their lawyers, to defend themselves" in federal court.

On May 4, ExxonMobil became the first US company to take advantage of President Donald Trump's administration lifting the suspension of Title III of the 1996 Helms-Burton Act.

The provision allows anyone whose assets were seized after the revolution to sue Cuban individuals and businesses profiting from the former holdings.

It had been suspended by all previous US presidents to avoid causing friction with allies, such as the European Union, some of whom view it as overstepping American jurisdiction.

Cuban television said "it's not the first time, nor is it unusual, for Cuban entities to defend their interests in the US judicial system," adding that it had happened more than 40 times.

Exxon is one of the companies born out of the now-defunct Standard Oil, whose refinery in Havana was one of the first American entities nationalized by Castro.

The refinery is currently operated by Cupet.

The US hopes the measures taken against Cuba will starve its socialist regime of much-needed foreign investment for its stuttering economy.

Cuba attracted only $2 billion in investments in 2017, well short of the $5 billion needed to spark growth.

The island nation suffers from a shortage of food, exacerbated by US sanctions first applied in 1962 and which the Trump administration has ramped up.