Mexico says it wants to eject migrants from Central America who tried to force their way toward the US-Mexico border near Tijuana.

The Mexican Interior Ministry said late Sunday that those who could be identified would be expelled.

Hundreds of Central Americans tried to force their way toward the US-Mexico border near Tijuana on Sunday. Police in Tijuana were overwhelmed as migrants pushed towards the border close to the San Ysidro crossing.

According to news reports, US security forces used tear gas to turn them back. The US closed the border crossing at San Ysidro for several hours in response.

Some of the migrants had crossed a foot bridge in Mexico about 3 kilometres from the border and then broke ranks and began to run towards a metal fence close to the San Ysidro border crossing, the Spanish-language Milenio news portal reported.

They chanted, "We are not criminals! We are international workers!" according to CBS News. The group was mostly men, although some women and small children were among them.

More than 4,700 Central American migrants have gathered in Tijuana after traversing Mexico during the last several weeks largely on foot in so-called caravans. They are currently waiting in a stadium in Tijuana for a chance to gain entry to the US.

The migrants are chiefly from Honduras, El Salvador and Guatemala.

Most reportedly say they are fleeing violence and poverty in their home countries and hope for asylum. Thousands more are travelling toward the border with the same aspirations.

The caravans have drawn a strong reaction from US President Donald Trump, who has sent active military troops to the border to support border guards. Trump returned to Washington following a trip to Florida over the Thanksgiving holiday weekend.

The United States Customs and Border Protection (CBP) reopened the busy border crossing at San Ysidro several hours after the earlier closure.

Pedestrian as well as southbound and northbound vehicle processing was open, CBP San Diego said in a series of Twitter posts late Sunday.

Earlier, Homeland Security Secretary Kirstjen Nielsen said the department "DHSgov will not tolerate this type of lawlessness & will not hesitate to shut down POEs for security reasons. We'll seek to prosecute to the fullest extent of the law anyone who destroys federal property, endangers our frontline operators, or violates our sovereignty," she said on Twitter.

Officials had been forced to close the crossing at San Ysidro "to ensure public safety in response to a large # of migrants seeking to illegally enter the US," she added.

On Saturday, the mayor of Tijuana had declared a "humanitarian emergency" and said the city cannot handle the expense of harbouring the migrants.

The CBP said in a news release on Saturday that agents at a different border crossing near Yuma, Arizona, had rocks thrown at them when they tried to arrest a subject who claimed to have been part of a migrant caravan.

The developments occurred after the incoming Mexican interior minister denied a report that the Mexican government had reached an agreement with Washington on how to handle migrants hoping to claim asylum in the US.

Mexican Interior Minister-designate Olga Sanchez Cordero said "there is no agreement with the US government," according to the newspaper Excelsior.

The Washington Post reported Saturday that Washington won the support of the incoming Mexican government for a policy that would require asylum seekers to remain in Mexico while their claims are processed in US courts.

Trump referred to such a policy in a series of tweets late Saturday and Sunday in which he restated his opposition to migrants being allowed into the US prior to a court approval of their asylum claims.

He wrote Sunday that it would be "very SMART" if Mexico would stop caravans before they reach the border, or if governments would prevent them from forming, suggesting countries were using it as a way to get "certain people" out and "dump" them in the US.