By Hugh Bronstein

BUENOS AIRES (Reuters) - Venezuela's Foreign Minister Delcy Rodriguez failed to get into a meeting of the Mercosur trade bloc on Wednesday after threatening to enter through the window if necessary, despite her country being thrown out of the group this month.

The meeting, at Argentina's foreign ministry in Buenos Aires, also grouped fellow South American nations Brazil, Uruguay, Bolivia and Paraguay.

"If they close the door to us we will, as our president (Nicolas) Maduro has said, go through the window," Rodriguez told reporters outside the ministry.

"We will put on rubber-soled shoes and get in through the window ... Venezuela does not need an invitation because it is for the time being president of Mercosur."

Venezuela was expelled from Mercosur this month in part due to concerns about the government's human rights record.

Maduro's socialist government, which has lost allies in the region as various countries have moved to the right, says its suspension from the bloc is an unjustified and illegal "coup".

The pugnacious foreign minister was later allowed into the ministry building, through the door, to meet with Argentine Foreign Minister Susana Malcorra. She stayed for about an hour before exiting without gaining access to the Mercosur session.

Malcorra later told reporters that she had made it clear to Rodriguez that while she was welcome to meet one-on-one with her at the ministry, Venezuela was not invited to the Mercosur conference.

"No one ever gets into a multilateral meeting without authorization. The minister obviously felt she had the right to attend, but she had been told explicitly, verbally and in writing, that she was not invited," Malcorra said.

The one-on-one meeting also proved fruitless, she added.

"We got into a circular discussion that was not going to get us to a concrete solution," Malcorra told a news conference.

"We have accepted that Venezuela has a different point of view, and that we will use mechanisms established by Mercosur for resolving conflicts. As a matter of fact tomorrow there will be a preliminary meeting among the parties in Montevideo to take the conversation further," Malcorra said.

Venezuela joined Mercosur in 2012.

(Editing by Bernard Orr)