The deployment of National Guard members to the U.S.-Mexico border at President Donald Trump's request was underway Tuesday with a gradual ramp-up of troops under orders to help curb illegal immigration.

The Trump administration also announced that Homeland Security Secretary Kirstjen Nielsen will visit this week a stretch of new border wall breaking ground in New Mexico, putting additional focus on what Trump has called a crisis of migrant crossings and crime.

A senior Russian lawmaker says Moscow is willing to help arrange a visit this week for experts from the international chemical weapons watchdog to the site of a suspected poison gas attack in Syria.

Syrian opposition activists say 40 people died in Saturday night's chemical attack in the town of Douma, the last remaining rebel bastion near Damascus. The opposition blamed President Bashar Assad's forces for the attack, accusations the government strongly denies.

Government and other scientists are proposing a new way to define Alzheimer's disease — basing it on biological signs, such as brain changes, rather than memory loss and other symptoms of dementia that are used today.

A 4.7-magnitude quake has hit an area of central Italy near Macerata which was struck by a series of powerful quakes in 2016. No deaths or injuries have been reported.

Mayors in towns affected are reporting some damage from the temblor, which struck around dawn, and said that checks were under way. Schools in many towns have been closed for the day, as was a local train line.

Lost amid a flurry of Facebook announcements about privacy settings and data access is a much more fundamental question: Is Facebook really changing its relationship with users, or just tinkering around the edges of a deeper problem — its insatiable appetite for the data it uses to sell ads?

North and South Korea on Saturday held talks over establishing a telephone hotline between their leaders and other communication issues ahead of a rare summit between the rivals later this month.

The closed-door talks between working-level officials at a border village were part of preparatory discussions to set up the April 27 summit between North Korean leader Kim Jong Un and South Korean President Moon Jae-in. The meeting, only the third summit between the Koreas since the end of the 1950-53 Korean War, could prove to be significant in the global diplomatic push to resolve the standoff over North Korea's nuclear program.

Prime Minister Saad Hariri contacted President Michel Aoun and Speaker Nabih Berri from Paris, and “congratulated” them on the “success” of the CEDRE conference that concluded Friday raising billions of dollars aimed at averting an economic fallout in Lebanon, Hariri's media office said.

The emir of Qatar will be meeting with President Donald Trump at the White House next week.

White House spokeswoman Sarah Huckabee Sanders says Sheikh Tamim bin Hamad Al Thani will be meeting with Trump on April 10.

Saudi air defense forces say they shot down a missile launched by Yemeni rebels at the southern Saudi border city of Jizan. The rebels say the attack was aimed at an Aramco oil facility.

In a statement late Wednesday, the Saudi-led coalition fighting the rebels known as Houthis said the attack caused shrapnel that landed in residential neighborhoods. It said the rocket was fired from the rebels' stronghold of Saada in northern Yemen.

A jury has awarded nearly $17 million to a former Ford engineer who sued the automaker for discrimination because he says two supervisors repeatedly berated and criticized him for his Arab background and accent.