A senior Republican senator has said that he is concerned about the group's attack on the United States as the Islamic State grows in Afghanistan and wars spread around the world.

Lindsey Graham stressed, "I've never been more worried about attacks on my homeland than I am now."

Senator Lindsey Graham, the top Republican US Senator, answered Margaret Brennan's questions in an interview with CBS News.

In response to a question about border security and related costs, he said that $100 billion is enough to strengthen border security, stressing that these measures are necessary to prevent external threats.

Lindsey Graham said, "I've never been more worried about attacks on my homeland. With the influence of ISIS in Afghanistan and wars around the world, I think the Republican's number one priority should be border security."

He also emphasised, "If we don't, we will be playing Russian roulette with our national security. Border security should be a priority, funding the army should be a priority. Then, let's cut taxes and costs."

"Russian roulette" is a type of game in which the participants place only one bullet in the magazine of the gun, and then the magazine is rotated several times, and then aimed at the head or body of one of the participants. Russian roulette is an allusion to a behavior based on luck.

Earlier, Michael McCaul, the former chairman of the US House of Representatives Foreign Relations Committee, also warned that ISIS has been revived in Afghanistan under the control of the Taliban.

The Taliban, however, claims to have eliminated ISIS in Afghanistan and that Afghan soil is not being used against foreign countries.

However, the report by independent international organisations shows that ISIS continues to recruit and expand its influence in Afghanistan. According to the UN Security Council report, ISIS has even infiltrated the Taliban's security institutions.