The Czech Foreign Ministry has rejected as groundless a Sudanese court's ruling that sentenced a Czech national to 20 years in prison.

The ministry said Petr Jasek was given the stiff prison term on Sunday by a court in Khartoum, where he was tried on charges that included espionage.

The ministry says a deputy foreign minister will travel to Sudan in the coming days to try to negotiate Jasek's release and if necessary, Foreign Minister Lubomir Zaoralek is ready go there, too.

Czech officials say Jasek was in Sudan to help local Christians and was arrested in December 2015.

In a statement on Sunday, the ministry said Jasek is in relatively good condition, but that there was no evidence to support his conviction or sentence.