Exclusive: North Korea oil imports, airline among possible U.S. sanctions targets - sources

By David Brunnstrom and Matt SpetalnickWASHINGTON (Reuters) - Despite sending a naval force to the Korean peninsula, the Trump administration is focusing its North Korea strategy on tougher economic sanctions, possibly including an oil embargo, banning its airline, intercepting cargo ships and punishing Chinese banks doing business with Pyongyang, U.S. officials say.U.S. President Donald Trump has approved a preliminary broad approach on North Korea and asked his national security team to craft