The opposition leader and self-proclaimed interim president Juan Guaido has said he is considering asking for an international military intervention in Venezuela.

Speaking to RTP envoy Helder Silva, he said all the options are on the table to down President Nicolas Maduro.

"Well, in theory and by what they said, all options are on the table; this allows anticipating that it is an alternative," he said.

Talking about "the best and fastest" solution to the ongoing crisis in Venezuela, which has left 40% of the population in complex humanitarian emergency, Mr Guaido alluded to Article 187 of the Venezuelan constitution, which allows for the "possibility" of the national parliament to authorise foreign military cooperation.

"We crossed the red line a long time ago", he concluded.

In another interview, the opposition leader said he has asked his envoy to the United States to meet with Pentagon officials to "cooperate" on a solution to the South American country's political crisis.

Mr Guaido added he had received word from China that the country would join a diplomatic effort between European and Latin American countries, known as the International Contact Group on Venezuela, to negotiate an end to the crisis.

Juan Guaido speaks to supporters during a demonstration against Nicolás Maduro

In January, Juan Guaido invoked the OPEC nation's constitution to assume an interim presidency, arguing President Nicolas Maduro's 2018 re-election was illegitimate.

He has been recognised by most Western and Latin American countries, but Nicolas Maduro has retained the support of allies China, Russia and Cuba.

Mr Guaido's effort to oust President Maduro so he can take power and call new elections has stalled in recent weeks, after an attempted military uprising on 30 April was put down.

He told an Italian newspaper this week that he would "probably" accept a US military intervention if the United States proposed it.

"We have instructed our ambassador Carlos Vecchio to meet immediately ... with the Southern Command and its admiral to establish a direct relationship," Mr Guaido said at a rally in Caracas.

"We have said from the beginning that we will use all the resources at our disposal to build pressure."

Read more:
Supreme Court orders Guaido deputy to be held in military prison
Deputy to Venezuela's Guaido arrested and dragged away by tow truck

Representatives of the US Southern Command and Mr Vecchio did not immediately respond to requests for comment.

Trump administration officials have repeatedly said that "all options are on the table" to oust Nicolas Maduro, who calls Juan Guaido a US puppet seeking to oust him in a coup.

The Southern Command said in a tweet on Thursday that it was prepared to discuss "how we can support the future role" of Venezuelan armed forces leaders who "restore constitutional order," when invited by Mr Guaido.

Venezuela's Information Ministry did not immediately respond to a request for comment.

Defense Minister Vladimir Padrino separately said that a US Coast Guard ship had entered Venezuelan territorial waters, which he said "we will not accept."

A Southern Command spokesman said yesterday that a US Coast Guard vessel was conducting a "counter-drug detection and monitoring mission" in "international waters" in the Caribbean Sea on 9 May.

Read more:
Government recognises Juan Guaido as President of Venezuela
EU nations recognise Guaido as Venezuelan president

Juan Guaido was speaking at a rally in support of opposition lawmakers who have been arrested, taken refuge at foreign embassies in Caracas, and been threatened in recent days amid a broad crackdown by Nicolas Maduro against congress after the uprising.

Most Latin American countries, as well as the European Union, have expressed opposition to potential military intervention in Venezuela.

EU foreign policy chief Federica Mogherini said last week the contact group is prepared to begin a "mission at the political level" in Caracas.

Additional Reporting Reuters