Buffett made the comments on the oil pipeline Monday morning in a wide-ranging interview with CNBC following the release over the weekend of his annual letter to shareholders of Berkshire Hathaway (BRKA), of which the legendary investor is chairman and CEO.

In the letter, Buffett said that Berkshire’s shares had risen nearly 2,000,000% since he took over the company 50 years ago. He also provided an update on the Heinz buyout, gave hints about his successor, said he had made a $100 billion blunder and even had some pretty good one-liners.

Buffett called the performance in 2014 of Berkshire’s railroad Burlington Northern Santa Fe disappointing. In response to a question about BNSF on Monday, Buffett said that if he were president he would have passed the Keystone pipeline. Buffett said he thought the pipeline would be good for both Canada and America. Buffett said it was also a mistake to jeopardize the trading relationship with Canada.

“Canada’s been a terrific partner for us over the decades and it is wrong for us to thumb our nose at them,” said Buffett.

Buffet didn’t criticized Obama by name and Buffett, a lifelong Democrat, has mostly been in agreement with Obama in the past. Obama has championed a Buffett suggestion that America’s 1% pay higher tax rates, calling it the Buffett Rule.

Buffett also said that Massachusetts Senator Elizabeth Warren, another Democrat who has regularly criticized Wall Street, would do better if she was less combative, and that he has told her that. “I think she would do better if she was less angry and demonizing,” said Buffett. “I’m not sure I have fully convinced Elizabeth Warren that’s the way to go.”

Buffett also used the interview to reiterate his support for Hillary Clinton. Earlier this year, Buffett said at Fortune’s Most Powerful Women summit that he would bet that Clinton would be the next president.

“Hillary Clinton is very likely to be the next Democratic nominee and very likely President of the United States,” Buffett said on CNBC on Monday.

On Mary Barra, GM’s CEO, Buffett said she was absolutely the right person for the job. Buffett said he thought it didn’t make sense for the company to elect a representative of a bunch of hedge funds to its board. He said the hedge funds and their chosen director appear to have too short a time horizon for boosting GM’s stock. And he said he isn’t upset about the fact that GM (GM) isn’t buying back it’s own stock.

“The government had to bail the car companies out,” said Buffett. “Things can change pretty quickly [for their finances].”

On Europe, Buffett said he thought the Germans and others shouldn’t give into Greece’s demands for debt relief. He said that would be encouraging bad fiscal behavior that could get the Euro in further trouble. He said Europe would be better off cutting Greece loose if it had to. And Buffett gave his own folksy spin on the situation.

“If you have a dog peeing on your carpet, you do not want to start giving it a bunch of dog biscuits,” said Buffett.