Two U.S. citizens have been arrested in Venezuela, part of a group of seven who President Nicolas Maduro on Tuesday branded as "mercenaries," in the latest roundup ahead of the embattled leader's expected inauguration to a new term later this week.

Venezuela's government is intensifying efforts to apprehend opposition leader Edmundo González, who claims to have defeated President Nicolás Maduro in last year's contentious election. On Sunday, National Assembly leader Jorge Rodriguez declared the immediate arrest of González if he sets foot in the country.