The International Committee of the Red Cross is to triple aid to Venezuela, a day after the crisis-riven country’s leader approved the delivery of humanitarian assistance.

The organisation announced the increase in the face of mounting calls for the UN to recognise the scale of the crisis facing Venezuela, and amid continued moves by the Trump administration to persuade other countries to back its calls for the removal of President Nicolás Maduro.

With the health system in collapse, and food and electricity shortages now commonplace, the Maduro government has been accused of deliberately minimising the scale of the problems facing the country even as millions have fled over its borders.

A joint report last week by Human Rights Watch and the Johns Hopkins Bloomberg School of Public Health urged the UN to take a lead in what it described as a “complex humanitarian emergency” that demanded a “full scale” international response.

The 71-page report documented rising maternal and infant deaths, the unchecked spread of vaccine-preventable diseases such as measles and diphtheria, and sharp increases in the transmission of malaria, tuberculosis and other infectious diseases.

Announcing the aid increase, the Geneva-based organisation said: “The ICRC has tripled its budget for operations in Venezuela from about $9m [£6.8m] to about $24.6m.

“The financial boost will see the ICRC expand its work on four pressing humanitarian issues: migration, health, water and sanitation, and detention.”

The pressure for increased aid to the oil-rich but imploding country follows clumsy efforts by the Trump administration to politicise the delivery of US aid to shore up support for opposition leader Juan Guaidó, whom Washington and dozens of other countries have backed as interim leader over Maduro.

Maduro, however, enjoys the support of Russia – a veto-wielding member of the UN security council – and Cuba.

The war of words between Washington and Caracas flared up again on Wednesday when Mike Pence, the US vice-president, called on the UN to revoke the credentials of Maduro’s representatives. On the same day, the US secretary of state, Mike Pompeo, described the Maduro government in Congress as “a true threat to the United States of America”.

For his part, Maduro has long denied the country is suffering from a humanitarian crisis and blames US sanctions for its economic woes.

Peter Maurer, the ICRC president, was in Venezuela this week, the first visit to the country by the organisation’s head in a quarter of a century.

“I am satisfied with the willingness of the authorities to work with us to address the humanitarian needs we have identified in a consensual way,” Maurer said in the statement.

The subject of humanitarian relief has become tense in Venezuela following a standoff over aid between Maduro’s government and Guaidó.

In January, Guaidó tried to spearhead a drive to bring in American aid, but the effort failed as the Venezuelan army blocked shipments at the Colombian border.

Maduro charged that the aid was a preamble to a military intervention to oust him from power.

Maurer said that during his visit he witnessed the suffering of ordinary Venezuelans “due to the deterioration of fragile basic services”, with hospitals struggling to ensure water, power, staff and basic supplies.

A quarter of Venezuela’s 30 million people are in urgent need of humanitarian aid, an internal UN report said last month.

The UN estimates that 3.7 million Venezuelans are malnourished and 22% of children below the age of five suffer from chronic malnourishment.