The nation's largest Latino advocacy group invited every 2016 presidential candidate to its annual convention next week, but no Republican candidates plan to attend, reported the Wall Street Journal.

The National Council of La Raza (NCLR), a Latino advocacy and civil rights organization, invited the 2016 presidential candidates to a lunch on Monday in Kansas City, Missouri. Democrats Hillary Clinton, the former secretary of state, Sen. Bernie Sanders of Vermont and Martin O'Malley, former Maryland governor, will attend.

Clinton is expected to outline her plans for immigration reform during the NCLR luncheon.

Ann Murguia, executive director of the Argentine Neighborhood Development Association, and the sister-in-law of NCLR President Janet Murguia, said she is disappointed Republican presidential candidates won't attend the event to discuss immigration reform.

"NCLR does not take a politically partisan position," Ann told WDAF-TV. "I've been going to NCLR conferences for years and I will tell you I have had the pleasure of meeting both republicans and democratic leadership. For example, one year I had the chance to meet President Obama, and Vice President Joe Biden, but also presidential candidate John McCain was there also."

Ben Carson, a retired neurosurgeon who is running for the GOP nomination, was the only Republican to attend the National Association of Latino Elected and Appointed Officials event last month in Las Vegas. Carson addressed Latino policymakers at the event on important issues to the Latino community, as did Democrats Clinton and Sanders who also attended.

While most Republican presidential candidates have neglected to attend Latino events, they are expected to attend a convention later this month of the National Urban League, a civil rights group that is mainly African-American. Republicans Jeb Bush, the former Florida governor, and Carson, as well as Clinton and O'Malley will attend, according to the organization.