Recent criticism of its stance by Venezuela's ambassador will probably force Ms Bachelet to abstain.
At an equivalent stage in her presidency, his predecessor, Michelle Bachelet, was similarly unpopular.
The secretary-general made no mention when he announced her appointment of what changed Bachelet's mind.
Under Chile's constitutional term limits, Bachelet could not run for a second consecutive four-year term.
Michelle Bachelet Jeria, a doctor of medicine, became the first woman president of Chile in 2006.
But under Michelle Bachelet, the president since 2006, it has run out of steam.
Mr Lugo himself has expressed admiration for Chile's Michelle Bachelet, a more moderate socialist.
Student leaders have repeatedly called for peaceful demonstrations - a call echoed by President Bachelet.
Pablo Bachelet makes an excellent point in a piece published in The Miami Herald this week.
CENTERFORSECURITYPOLICY: The Importance of Ratifying Free Trade Agreements
The charges follow a forensic report into the death in prison of Gen Alberto Bachelet in 1974.
BBC: Chile charges two over General Alberto Bachelet's death
Mr Morales will be on hand when Michelle Bachelet is sworn in next month as Mr Lagos's successor.
Women worry that whatever good Ms Bachelet does for them specifically will be undone if she fails generally.
ECONOMIST: Will Michelle Bachelet help women or hinder them?
Chile has been wavering: Michelle Bachelet, the president, leans towards Venezuela, but much of her centre-left coalition does not.
Ms Bachelet began her assault on inequality by appointing women to half the cabinet posts in her centre-left government.
ECONOMIST: Will Michelle Bachelet help women or hinder them?
Again echoing Mr Lagos, Ms Bachelet promises to do more to tackle inequality.
ECONOMIST: Chile's new president promises continuity and change
It may have helped that Ms Bachelet is a medical doctor by profession.
But Ms Bachelet has promised many fresh faces in a cabinet half of whose members, she says, will be women.
ECONOMIST: Chile's new president promises continuity and change
Ms Bachelet is also being criticised for running too tight a ship, thus undermining her ministers' ability to produce results.
Michelle Bachelet, Executive Director of UN Women, opened the meeting, along with Georg Kell, Executive Director of the UN Global Compact.
FORBES: Calling all Global CEOs -- Have You Signed the UN Women's Empowerment Principles Yet?
"It is not common for a president to stand before the nation and say 'Things haven't gone well, " Bachelet said in Spanish.
Many of her countrymen put Ms Bachelet's problems down to her sex.
ECONOMIST: Will Michelle Bachelet help women or hinder them?
The inhabitants of Santiago, especially the poorest, " Bachelet said, "deserve an apology.
His approval ratings in opinion polls have leapt over the past few months, as have those of his boss, Michelle Bachelet, Chile's president.
To address fears of becoming isolated from a sometimes unstable neighbourhood, Michelle Bachelet, the current socialist president, has stressed closer ties with Latin America.
Bachelet was tipped as a possible leader of the agency immediately after the General Assembly voted unanimously in July 2010 to create UN Women.
Bachelet is widely expected by Chileans to be a candidate in the Nov. 17 presidential election, though she did not address the political angle.
In the past 12 months Ellen Johnson-Sirleaf became president of Liberia, Michelle Bachelet president of Chile and Han Myung-sook South Korea's first female prime minister.
So troubled is Santiago's new mass transit system, known as Transantiago, that President Michele Bachelet made an unusual admission just days after its disastrous roll-out.
The socialist countries in Latin America including President Michelle Bachelet of Chile also commended Ecuador's President, Rafael Correa, for his victory in the constitutional referendum.
应用推荐