The White House is preparing to end asylum access for anyone who enters the US illegally. The executive order will limit entry to official US Ports of Entry, the same principle used in the Trump administration's travel ban. The official decree is expected on Friday and is likely to immediately face challenges in court. The move comes as a caravan of thousands of migrants is slowly crossing Mexico toward the United States. But as CGTN's Alasdair Baverstock reports, many of those who have reached Mexico City are carefully planning their next move.

As the Central American migrants who've made it to Mexico City take some time to rest, plans are being laid for their next moves. The nearest US border is more than a thousand kilometers away, and no one here knows what awaits them when they arrive. As their numbers grow in the stadium where they are being housed, international authorities are doing their best to deal with this growing humanitarian crisis.

CHRISTOPHER GASCON, DIRECTOR UN MIGRATION AGENCY "We estimate that more than 10,000 people have crossed Mexico's southern border, of which 18-hundred have asked for refugee status. The rest are going to continue their route with the caravan. Five to six thousand are here in Mexico City, and more are still to arrive."

For at least those 18-hundred migrants the United Nations identified, establishing a new life in Mexico is preferable to the uncertainty of what awaits them at the US border.

GEORGINA MONTEROSA SALVADORAN MIGRANT "The border at the moment is very difficult to cross, because so many caravans are arriving, there is little chance of remaining in the US. So at the moment, we're looking for permission to work in Mexico for a while, and as time goes by, I'll be able to get my Mexican papers."

But for the majority, according to local authorities and most of the migrants CGTN spoke with in the caravan, the United States remains the ultimate goal.

JUAN JOSE GALDAMES HONDURAN MIGRANT "Our plan is to continue. It makes me scared, be he who doesn't risk anything, never gets anything."

While some conservative politicians in the U.S. have demonized these travelers, we found dozens of sympathetic Americans here on the ground, offering their help. Tristan Call from Nashville, Tennessee, is part of a contingency from the American migrant aid group Pueblo Sin Fronteras, which has been guiding and advising the caravan since its journey began in Honduras last month. He says his main focus is giving solid advice to the migrants on what to expect if they continue north, and outlining their option to stay in Mexico.

TRISTAN CALL PEOPLE WITHOUT BORDERS "What we're trying to do is get people information that is as up-to-date and as good as we can about what this accelerated and more open process that Mexico is trying to do with work permits and residency. We want people to know what they're likely to face, so that they're able to make some of those decisions."

ALASDAIR BAVERSTOCK MEXICO CITY "While Americans may be helping here, President Trump's administration has made it clear that the migrants are not welcome in the United States. More than five thousand U.S. troops have been deployed along the border to bolster National Guard and other border patrol forces already in place. And Trump has said he's prepared to send 10-thousand more troops if needed to keep the migrants at bay."

As caravan members decide on their individual futures, the US border prepares for their approach. And the decisions made at this critical pit stop may determine how many migrants ultimately arrive. Alasdair Baverstock, CGTN, Mexico City.