(CNN) -- NATO should extend membership to two former Soviet republics, and any Russian invasion of a NATO state could lead to a conflict with the U.S., Republican vice presidential candidate Gov. Sarah Palin told ABC News.
However, the United States and Russia "cannot repeat the Cold War," the Alaska governor said in her first interview since becoming Sen. John McCain's running mate.
ABC released excerpts of Palin's interview with "World News Tonight" anchor Charlie Gibson on Thursday. The full interview is scheduled to air Friday night on the network's "20/20" program.
Palin said she supported NATO membership for Ukraine and Georgia -- a move Russia strongly opposes. She also said the United States must be "vigilant" about larger powers invading small democracies. Watch Palin say war may be necessary »
The interview comes just over a month after Russian troops invaded Georgia in support of separatist governments in two Georgian territories -- a step that led to widespread condemnation from the West and a tit-for-tat freeze in Russia-NATO ties.
"We have got to show the support, in this case, for Georgia. The support that we can show is economic sanctions perhaps against Russia, if this is what it leads to," she said.
"It doesn't have to lead to war and it doesn't have to lead, as I said, to a Cold War," Palin said, "but economic sanctions, diplomatic pressure, again, counting on our allies to help us do that in this mission of keeping our eye on Russia and [Russian Prime Minister Vladimir] Putin and some of his desire to control and to control much more than smaller democratic countries."
When Gibson pointed out that NATO membership would require the U.S. to come to Georgia's aid in case of war, Palin said: "Perhaps so."
"I mean, that is the agreement when you are a NATO ally, is if another country is attacked, you're going to be expected to be called upon and help," she said.
Palin said Putin's goal is "to control energy supplies" coming from or through Russia.
"That's a dangerous position for our world to be in, if we were to allow that to happen," she said.
Critics have questioned Palin's experience since McCain chose her as his running mate August 29. She has been governor of Alaska for less than two years and served as mayor of her hometown of Wasilla, outside Anchorage, for six. iReport.com: Share your thoughts on Palin and the election
But Palin said she "didn't blink" when McCain offered her the GOP vice presidential nomination and is confident she could handle the duties of president if necessary.
"When John McCain and I are sworn in, if we are so privileged to be elected to serve this country, we'll be ready. I'm ready," Palin said.
Palin has touted herself as a small-town "hockey mom," a pit bull in lipstick who has taken on corruption in her own party at home and pushed for expanding oil and gas production in her vast, resource-rich state.
But her claim to have opposed the infamous "bridge to nowhere" in Alaska has been called into question, and she faces an investigation at home into allegations that she abused her office by trying to get her ex-brother-in-law fired from the Alaska State Troopers.
Palin has denied wrongdoing in the matter.
The 44-year-old Palin is the mother of five children. The oldest, 19-year-old Track, is an Army private who is about to ship out to Iraq.
She said she is "so proud" of her son for his "independent and strong decision" to join the military -- "serving for the right reasons and serving something greater than himself and not choosing a real easy path where he could be more comfortable and certainly safer."