WASHINGTON (Reuters) - The U.S. State Department on Monday said there can be no "business as usual" with Myanmar's ruling military following its execution of four democracy activists, adding that it was considering further measures to punish the military government. 

A United Nations human rights expert on Monday also called on countries to take steps against Myanmar's ruling military through economic sanctions and an arms embargo following the execution of four democracy activists.

Myanmar's ruling military announced on Monday it had executed four democracy activists accused of aiding "terror acts", sparking widespread condemnation of the country's first executions in decades.

Speaking at a regular press briefing, State Department spokesperson Ned Price also called on countries to ban sales of military equipment to Myanmar as well as the ASEAN grouping to maintain precedent of barring military representatives from regional meetings.

Asked in an interview what should be done in response, U.N. Special Rapporteur on human rights in Myanmar Tom Andrews also said: "There are a number of options and what we need to see is the international community start to seize them."

"The first option, the best option, is for the U.N. Security Council to convene to pass a strong resolution of not only condemnation, but clear strategic action, sanctions, economic sanctions and arms embargo" and refer the case to the International Criminal Court, he added in the same interview from Washington.

He called for more support for the humanitarian response, which was just 10% funded, and more coordinated engagement with the shadow government in Myanmar the National Unity Government (NUG), which is leading efforts to undermine the ruling military.

Officials at Myanmar's embassy in Washington and its diplomatic mission in Geneva did not immediately respond to requests for comment on Andrews' remarks. 

The ruling military has previously defended the death sentences as justified and used in many countries.