The United States, for the first time, imposed sanctions on the Syrian President Bashar al-Assad and six of his top aides for human rights abuses on Wednesday.

In a letter to the Congress, President Barack Obama called the sanctions a response to the continuous escalation of violence against the people of Syria.

Both EU and US were reviewing fresh penalties, which are expected to act fast. We will be taking additional steps in the days ahead, said Secretary of State Hillary Clinton a day before the sanctions were imposed.

The US has stopped short of asking Assad to step down, but there is now pressure on Syria to stop its brutal attack on protesters. The statement came a day before President Obama delivers a speech on the political situation in the Arab world.

Imposing sanctions on Assad, which the United States and European Union have avoided so far, has raised questions about whether the EU and US will seek the removal of Assad from power.

The U.S. administration has condemned the violent attacks on protesters and imposed similar sanctions several weeks ago on the second-tier officials in Syria.

The Treasury Department, says it will freeze the assets of Syrian officials in the United States or those which fall within the U.S. jurisdiction. It also bars U.S. companies and individuals from dealing with them, reports Reuters.

The sanctions also include Vice President Farouq al-Shara, Prime Minister Adel Safar, Interior Minister Mohammad Ibrahim al-Shaar, chief of Syrian military intelligence Mohammed Dib Zaitoun, director of political security directorate, Defense Minister Ali Habib and Abdul Fatah Qudsiya.

The message to the Syrian government is that they “will be held responsible for the ongoing violence and repression in Syria the Syrian leadership,” said David S. Cohen, acting Secretary for terrorism and financial intelligence, in a written statement.

President al-Assad and his regime must immediately end the use of violence, answer the calls of the Syrian people for a more representative government, and embark upon the path of meaningful democratic reform, Cohen added.

The European governments also agreed on Tuesday, to tighten sanctions against the Syrian government.