Trump Travel Ban 3 Proclamation 9645 bans all citizens from 12 countries.  The ban has no expiration date.  Green cards, visas or travel documents already issued will not be revoked.  A waiver of the ban is possible on an individual basis.

Restrictions by Country

North Korea	Entry as immigrants and nonimmigrants suspended.
Syria	Entry as immigrants and nonimmigrants suspended.
Yemen	Entry as immigrants and nonimmigrants on some business and tourist visas suspended.
Libya	Entry as immigrants and nonimmigrants on some business and tourist visas suspended.
Somalia	Entry as immigrants suspended, and nonimmigrants traveling to the United States to face enhanced screening and vetting requirements.
Iran	Entry as immigrants and as nonimmigrants suspended, except under valid student and exchange visitor visas — with enhanced screening and vetting requirements.
Venezuela	Entry of certain Venezuelan government officials and their immediate family members as nonimmigrants on some business and tourist visas suspended.
Nigeria	Entry on all immigrants visas suspended, except on Special Immigrant Visas.
Eritrea	Entry on all immigrants visas suspended, except on Special Immigrant Visas.
Tanzania	Entry under the Diversity Lottery Program.
Sudan	Entry under the Diversity Lottery Program.
Kyrgyzstan	Entry on all immigrants visas suspended, except on Special Immigrant Visas.
Myanmar (Burma)	Entry on all immigrants visas suspended, except on Special Immigrant Visas.

*Unlike the original ban, the new restrictions only include categories of immigration visa applicants. Specifically, all immigrants from Burma, Eritrea, Kyrgyzstan and Nigeria will be banned from the US. However, only green card lotteries will be restricted from Sudan and Tanzania, said a DHS official Friday.

A nonimmigrant is someone coming to the U.S. temporarily as a visitor, student, or employee. An immigrant is someone wanting to become a permanent resident of the U.S.

Waiver: Consular officers have discretion to waive the new restrictions on a “case-by-case basis” if a foreign national demonstrates:

1. Denying entry into the US would cause “undue hardship”; and
2. The foreigner does not pose a threat to national security.

A waiver application can be submitted at the time of visa interview at a U.S. consulate abroad or thereafter. Here is an AILA Practice Advisory regarding a waiver application.

As things currently stand, it is very likely a waiver application will be stalled and not easily processed or approved by the U.S. government due to a bias against immigration generally and in particular these banned countries.  

A waiver is possible in theory because any law that totally bans a race, religion, or nationality will likely be struck down in court on Constitutional grounds. So, the Trump Administration allowed for a waiver on an individual basis.

It is likely very few waiver cases will be approved, at least not initially.

Second round of litigation is very likely if only a few waivers are approved. It is important that your waiver be prepared in a manner that helps support that future litigation effort.

A poorly prepared waiver cannot withstand litigation efforts. It will be open to rebuttal and attack by the U.S. government, undermining your claim. There is every reason to bar a loved one from the U.S. if the waiver application is not well-prepared and presented. It opens the door for an excuse by the government not to approve and so will not withstand litigation.

We prepare our waiver applications in anticipation of second-round litigation. A well-prepared waiver can hold up in court and join the group of cases that may be successful. The U.S. government will be hard-pressed to explain the failure to grant a waiver in your case if prepared well.

Generally speaking, it’s very unfortunate for many families that this travel ban interferes with family relationships. We trust and hope that national security interests will be considered carefully, and that most families will eventually be allowed to come together.