A stockpile of USA aid - medicines, medical equipment and nutritional supplements - is in the Colombian border city of Cucuta.
Tensions in Venezuela escalated when Juan Guaido, the head of the opposition-led parliament, declared himself interim president on 23 January, disputing last year's re-election of incumbent President Nicolas Maduro.
Guaido asked supporters to participate in a mass mobilization, saying it may be up to the people to bring the aid into the country.
CGTN's Toby Muse is at the Colombia-Venezuela border.
Dr. Katia Diaz, a psychiatrist, said that each day aid sits waiting for transport into Venezuela represents one more day in which patient lives are at risk.
Maduro said he will make "the sufficient investment for Venezuela" to strengthen its anti-aircraft and anti-missile defense system, and equip the militia with "even the most modern missiles in the world".
Man City using past glory in title race - Silva
The loss left them outside the Champions League places and the pressure is mounting on manager Sarri. "Something is changing. Jurgen Klopp's side must respond in their next league game, which happens to be against United at Old Trafford in two weeks.
"Here are armed forces and here are the people to defend the honor, dignity and decorum of a country that has over 200 years of fighting for its future".
Trump has not ruled out USA military action for Venezuela, but has not specified under what circumstances he would send in US forces.
On Sunday, the Venezuelan military announced it had started conducting exercises, set to run until February 15 across the country, to "reinforce the country's defensive capacity".
It further "calls for the immediate start of a political process leading to free, fair and credible presidential elections, with worldwide electoral observation, in line with Venezuela's constitution".
Venezuela's self-proclaimed interim leader has told RT that the "corrupt regime" there is exclusively to blame for its dire humanitarian situation, and promised that democracy will be embraced, with free elections, once Maduro is gone.
Under Maduro's stewardship, oil-rich Venezuela's economy has collapsed leaving the country wracked by hyperinflation, recession and shortages of basic necessities such as food and medicine.