The Venezuelan government has given the German ambassador 48 hours to leave the country after he expressed support for opposition leader Juan Guaido.
Foreign minister Jorge Arreaza tweeted a statement saying Ambassador Daniel Kriener interfered in Venezuela's internal affairs and allied himself with "extremist sectors" of the opposition.
Kriener and other top diplomats greeted Guaido when he returned to Venezuela on Monday and vowed to intensify his campaign to topple the government of President Nicolas Maduro.
Waiting for Guaido at the country's main airport, Kriener spoke to media and said he hoped the leader of the National Assembly would have a safe return.
There were concerns that the opposition leader might face detention, but Maduro's government did not move against him.
The government declared Kriener persona non grata and gave him 48 hours to leave the country, accusing him of meddling in internal affairs, although it did not give specific details.
"Venezuela considers it unacceptable that a foreign diplomat carries out in its territory a public role closer to that of a political leader aligned with the conspiratorial agenda of extremist sectors of the Venezuelan opposition," the government said in a statement.
After confirming Venezuela's expulsion order, the German Foreign Ministry said it was co-ordinating how to proceed, "including with our partners on the ground".
The United States and some 50 other countries have recognised Guaido as the legitimate leader of Venezuela and have urged Mr Maduro, to resign so the country can prepare for elections.
Maduro says he is the target of a US-backed coup plot.
