The US import ban on Russian oil may lift the country's sanctions against Venezuela and President Nicolás Maduro has opened up to increase oil production.

Now there are more signs that the cold relationship between the countries may be heating up.

After a US delegation discussed energy supplies with Maduro this weekend, Venezuela has released two US citizens.

The first is Gustavo Cardenas, a former head of the oil company Citgo.

He was arrested in 2017, accused of corruption, along with six other Citgo employees with either US citizenship or a permanent residence permit.

All have been sentenced to long prison terms and the White House has repeatedly asked for their release.

Several were still imprisoned

Citgo is the US subsidiary of Venezuela's state oil company PDVSA and the US government has accused Venezuela of holding the imprisoned Citgo employees hostage.

Lawyer Jesus Loreto confirms that Cardenas has been released, but says the other five are still in custody.

The other American who has been released from Venezuelan prison is Jorge Alberto Fernandez, who was arrested last year near the border with Colombia accused of terrorism.

A human rights organization says on Twitter that Fernandez has been released and that the accusations against him are unfounded.