By Delphine Schrank

TECUN UMAN, Guatemala, Oct 20 (Reuters) - Hundreds of Central Americans in a U.S.-bound migrant caravan were stuck on Guatemala's border with Mexico on Saturday as efforts began, under pressure from Washington, to send some home and stop their journey northward.

Many of the migrants, the overwhelming majority fleeing violence and poverty in Honduras, had slept through heavy rain overnight on a bridge connecting Guatemala to Mexico, as dozens crammed against a metal border gate guarded by Mexican police.

In the early morning hours, Guatemalan police said they had transported 62 Hondurans in two buses, among the first such efforts to remove migrants from the tense border crossing on the Suchiate River.

For days U.S. President Donald Trump has warned the Central American caravan must be stopped. He has made it a political issue in the Nov. 6 midterm U.S. congressional election, threatened to cut off regional aid, close the U.S.-Mexico border and deploy troops there if Mexico failed to halt the migrants.

Honduran President Juan Orlando Hernandez was due to meet his Guatemalan counterpart Jimmy Morales in the Guatemalan capital on Saturday for talks on implementing a strategy for returning the Honduran migrants.

Organizers said the caravan included around 4,000 migrants on Friday but there has been no official estimate of the sprawling number of men, women and children traveling north on foot and in vehicles.

"The (U.S.) tone is one of worry and they told us that we should act like allies," a senior aide to Guatemala's president told Reuters, requesting anonymity as he was not authorized to speak publicly.

"It's really a very delicate situation because this could generate more caravans," he said.

On Friday, hundreds of migrants at the head of the caravan had poured through Guatemalan border posts and onto the bridge, but were repelled by dozens of shield-bearing Mexican police. Several complained they had been teargassed.

Drained from days of walking and frustrated, many spent the night in the open. Some stretched towels and garbage bags along the bridge walls, others lay down on backpacks, while a man applied lotion to his tired feet.

Mexico's government, which says it will process migrants' claims for asylum individually, vowed to tackle the caravan as U.S. Secretary of State Mike Pompeo met top officials in Mexico City. Pompeo urged Mexico to ensure the procession did not reach the United States.

Most of the migrants Reuters spoke to said their ultimate destination was the United States. Some said they hoped to stay in Mexico, but they had no idea how to get the documentation needed to do so.

Still, many were determined to try.

"No, I'll fight. I'll try again," said Honduran Hilda Rosa as her four teenage children sat upright, beaming as she pumped the air with her fist.

The native of Tegucigalpa told a familiar tale when asked why she had left Honduras: "You know why: no work, violence."

SOME TURNING BACK

Most of the people now caught trying to enter the United States illegally hail from Honduras, El Salvador and Guatemala, among the poorest and most violent countries in the Americas.

The caravan members ranged from farmers and bakers to housewives and students, and included a whole block of friends and family from the Honduran city of El Progreso, some of whom said they would start going back to where they came from on Saturday.

Jose Ramon Rodriguez, 45, a construction worker from El Progreso, sat on the Guatemalan end of the bridge late on Friday with his head hanging low, his 9-year-old son tucked against him.

"Tomorrow we go home," he said. His companions nodded.

Among them was Osman Melgar, who nursed a bleeding gash on his shin, suffered when he fell as dozens of people packed on the bridge began fleeing when police, according to several eyewitnesses, used tear gas.

Some, including 40-year-old Adriana Consuelo, went under the bridge, paying raftsmen 25 pesos ($1.30) to ferry them across the river on vessels made of giant rubber tires.

After making it to the muddy banks of Mexico, she said, "No one checked my documents," as Consuelo headed to a taco restaurant.

But Mexico had stepped up its efforts to stop the flow of people, migration experts said.

"Every time there's a (migrant) caravan there are police sent to the southern border ... but we've never seen anything as dramatic as we're seeing today," said Eunice Rendon, coordinator of migrant advocacy group Agenda Migrante.

"This has everything to do with Trump," she added.

($1 = 19.2570 Mexican pesos) (Reporting by Delphine Schrank; Additional reporting by Sofia Menchu in Guatemala City and Anthony Esposito in Mexico City; Editing by Dave Graham, Simon Cameron-Moore and Tom Brown)

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