US health authorities are investigating the passing of a three-year-old Venezuelan girl who was traveling with her parents on a bus transporting asylum seekers from Texas to Chicago.

Amid a controversial program, thousands of migrants have been relocated from Texas to US cities governed by the Democratic Party.

The young girl was taken to a hospital in southern Illinois and declared deceased on Thursday.

While Texas officials confirmed her demise on Friday, they refrained from divulging further specifics.

Originating from Brownsville, a city situated on the Mexico border, the bus conducted health assessments, including temperature checks and inquiries about medical conditions, for passengers before embarking on its journey out of the state.

Upon observing signs of the girl's health deteriorating, the bus made an unscheduled stop and onboard security personnel promptly contacted 911, according to officials.

Officials from the Texas Division of Emergency Management said that "every loss of life is a tragedy".

Republican governor Greg Abbott of Texas has sent more than 30,000 migrants to cities controlled by the Democrats since last year under his "Operation Lone Star" policies.

Last month, the US Department of Justice sued Mr. Abbott for his refusal to remove a floating barrier placed on the Rio Grande River aimed at stopping migrants from entering the US from Mexico.

The latest tragedy comes weeks after an eight-year-old girl died at a US border patrol site in Texas.

Venezuela's refugee crisis is the world's second-largest. More than seven million Venezuelans have left since 2015 due to the country's political and economic troubles.

What a tragedy!

Too bad

Too bad

Too bad

So sad