President Nicolas Maduro's government on Tuesday sharply criticised a UN-EU conference on Venezuela's refugee crisis, calling it a "hypocritical" exercise by countries seeking to isolate

Caracas. The slapdown was delivered by Venezuelan Foreign Minister Jorge Arreaza on Twitter after the two-day gathering -- to which Caracas was not invited -- wrapped up in Brussels on Tuesday.

His response contrasted with the view of the organisers -- and the US representatives who took part -- who hailed it as a success.

Even though it was meant to prepare the ground for a future pledging conference, several EU countries and the United States used it to announce more than 100 million euros ($110 million) in donations to help cope with the crisis.

A collapsing economy under Maduro, who remains in power through the support of his security forces, has prompted more than 4.5 million Venezuelans to leave, most of them to Latin American countries including Colombia, Ecuador, Peru and Brazil.

That outflow is expected to grow to 6.5 million in the coming year, rivalling the refugee crisis from Syria, the conference put together by the European Commission and the UN refugee and migration agencies UNHCR and OIM was told.

Despite punishing US sanctions and demands from the United States, the EU and most Latin American nations pushing Maduro to allow genuine elections to choose a successor government, a political solution remains elusive.

"In the meantime, we cannot avoid giving an urgent response to the humanitarian situation that Venezuelans and the host communities are facing," EU foreign policy chief Federica Mogherini told the conference.

She said the event was an important step in providing "an urgent response to the humanitarian situation that Venezuelans and the host communities are facing".

- US 'optimistic' over its strategy -

But Arreaza, in his tweet, dismissed the conference as "cynicism".

"The EU, UNHCR and OIM brought together governments blocking the Venezuelan economy, creating suffering and migration, stealing resources and threatening to isolate and attack Venezuela. A sad scramble for resources under the hypocritical pretext of a 'preoccupation' for migration," he said.

The United States, which has thrown its weight behind Venezuelan opposition leader Juan Guaido as the "legitimate" leader and Maduro as a "dictator" kept in power through support from Cuba and Russia, said the conference showing international unity.

A US State Department official focused on Latin America, Carrie Filipetti, told reporters after the conference that Washington's strategy of sanctions and supporting Guaido was yielding "a lot of successes".

"Of course the Maduro regime continues to deploy the tool that all dictators deploy when they're at wit's end, which is brutality and harassment and intimidation," she said.

But she added that "we are seeing a lot of positive momentum on our side. We're very optimistic about where this is heading."

She hailed "a growing international coalition" recognising Guaido as Venezuela's interim president and "considering more pressure options to force Maduro to come to the table to negotiate in good faith".afp, photo by Cancilleria del Ecuador/wikimedia.