The Obama administration is expelling Syria’s most senior envoy in Washington, joining a host of other governments in kicking out Syrian diplomats to protest last week’s gruesome massacre in which entire families, including children, were shot execution-style in their homes.

The State Department said Tuesday that the charge d’affaires at the Syrian Embassy has been given 72 hours to leave the United States. Syria has not had an ambassador in the United States since the previous envoy left last year to take another post.

State Department spokeswoman Victoria Nuland said the U.S. holds “the Syrian government responsible for this slaughter of innocent lives.”

German, Italian, Dutch and Spanish foreign ministries also announced that Syrian ambassadors were being expelled — following similar moves by France, Britain, Australia, and Canada after a massacre in which the United Nations says families were shot at close range in their homes.

The ambassador to Germany, Radwan Loutfi, was given 72 hours to leave Germany on Tuesday.

Foreign Minister Guido Westerwelle said Germany and its allies hope “that this unambiguous message does not fall on deaf ears in Damascus.”

The Italian Foreign Ministry said Ambassador Khaddour Hassan was called to the ministry and informed of his new status — which was also extended to an unspecified number of Syrian functionaries.

Spain said it was giving Syrian Ambassador Hussam Edin Aala and four other diplomats based in Madrid three days to leave the country.

Hours later, the Netherlands announced it had declared the Syrian ambassador persona non-grata, according to Reuters.

Earlier Tuesday, French President Francois Hollande said Syria’s ambassador is being expelled amid continuing violence by Syrian government forces against civilians and opposition members.

Hollande told reporters in Paris on Tuesday that the ambassador would leave “today or tomorrow.” He gave no other details.

The Syrian Embassy in Paris could not immediately be reached for comment.

The announcement came amid increasing diplomatic efforts to end the bloodshed in Syria and put pressure on Syrian President Bashar Assad.

The UN said Tuesday that entire families were shot in their homes during a massacre in Syria last week that killed more than 100 people, including children in the west-central area of Houla.

Australia also expelled two Syrian diplomats on Tuesday in response to last week’s massacre.

Charge d’Affaires Jawdat Ali, the most senior Syrian diplomat in Australia, and another diplomat from the Syrian Embassy were ordered to leave the country within 72 hours, Australian Foreign Minister Bob Carr told reporters. Carr said he expected other countries to do the same later Tuesday.

“This is the most effective way we’ve got of sending a message of revulsion of what has happened in Syria,” Carr said.

In a statement, Carr called the killings a “hideous and brutal crime” and said Australia would not engage with the Syrian government unless it abides by a UN cease-fire plan.

Also on Tuesday, British officials said the UK is expelling three Syrian diplomats. The officials, who demanded anonymity to discuss the action ahead of a planned public statement from Foreign Secretary William Hague, said that Britain was taking the step as part of a coordinated effort with other nations. Canada also announced the expulsion of Syrian diplomats on Tuesday.

The UN estimates 9,000 people have been killed since the uprising began in March 2011.