Tehran, Jun 30 (IANS): Iranian Foreign Minister Javed Zarif on Friday called the revised US ban on travellers from six Muslim-majority countries as "truly shameful".

"The US now bans Iranian grandmothers from seeing their grandchildren, in a truly shameful exhibition of blind hostility to all Iranians," Zarif said in a Twitter post.

He said earlier that Washington's move to exert bans on Muslims and prevent them from entering the US will not help that country to overcome its problems or become a safer place, IRNA news agency reported.

"A bigoted ban on Muslims will not keep the US safer. Instead of policies empowering extremists, the US should join the real fight against them," Zarif said.

President Donald Trump's revised travel ban came into force late on Thursday.

The new rules tighten visa policies affecting citizens from six Muslim-majority nations: Sudan, Syria, Iran, Libya, Somalia, and Yemen. People from those countries who need new visas will now have to prove a close family relationship or an existing relationship with an entity like a school or business in the US.

Citizens of those countries who already have visas will be allowed into the US as usual.

Trump said the 90-day ban on visitors from the six Muslim-majority countries -- and a 120-day ban for refugees from any country -- is necessary to block terrorists from entering the US.