CARACAS (REUTERS) - Venezuelan pro-government lawmakers will return on Tuesday (Sept 24) to the opposition-controlled Congress after a two-year absence, President Nicolas Maduro said on Monday, while maintaining that the institution was still illegal.

"Let's go to the debate, let's go to the fight," Maduro said on state television.

Maduro declared the National Assembly to be illegitimate in 2017 after the opposition won congressional elections two years earlier, spurring the creation of a parallel pro-government legislature to override opposition delegates' decisions.

Maduro on Monday insisted the assembly was still in contempt of the law, but said pro-government lawmakers would retake their seats as part of a deal struck with a small group of opposition delegates. "They will return to promote dialogue," he said.

This group is different from the coalition of opposition parties led by US-backed opposition leader Juan Guaido, the head of the National Assembly who invoked the Constitution to assume a rival presidency in January.

Guaido earlier this month said negotiations in Barbados between the opposition and government mediated by Norway "had been exhausted" after the Maduro administration withdrew delegates in August following a tightening of US sanctions.

Maduro also announced on Monday he would shortly leave for an official visit to Russia to improve "international cooperation", just as Latin American countries at the UN General Assembly were evaluating whether to apply new sanctions against his government.