Here are the stealthy jets the U.S. is offering to South Korea

As tensions on the Korean Peninsula rise, the Defense Department officially told Congress that the U.S. may sell 60 stealthy jets to South Korea.

Last Friday, the Defense Security Cooperation Agency — the arm of DOD that handles foreign military sales — announced the possible sale of 60 Lockheed Martin-made F-35 Joint Strike Fighters for $10.8 billion or 60 Boeing-made F-15SE Silent Eagles for $2.4 billon to the Republic of Korea.

The two U.S. defense giants have been pushing their premier export fighters on Seoul for years under the South Korean air force’s effort to replace its ancient F-4 Phantoms and F-5 Tigers with a 21^st century fighter, a contest known as FX III.

The U.S. jets are competing against the Eurofighter Typhoon, one of the most advanced operational fighters in the world.

"The proposed sale will augment South Korea’s operational aircraft inventory and enhance its air-to-air and air-to ground self-defense capability, provide it with a credible defense capability to deter aggression in the region, and ensure interoperability with U.S. forces," reads DSCA’s April 3 announcement of the possible F-15SE sale. "The Republic of Korea Air Force’s F-4 aircraft will be decommissioned as F-15SEs are added to the inventory. Korea will have no difficulty absorbing this additional equipment and support into its inventory. "

The April 3 notice of the possible F-35 sale has a nearly identical paragraph with an additional sentence that reads: "The proposed sale of F-35s will provide the Republic of Korea (ROK) with a credible defense capability to deter aggression in the region and ensure interoperability with U.S. forces."

While the fighter contest has been going on since 2012, the notification to Congress comes as tensions are running high between the U.S. and North Korea. Last week U.S. F-22s and B-2 stealth bombers flew over the Korean Peninsula, the U.S. Navy sent two additional destroyers to the region, and the Pentagon announced that it is sending missile defense units to Guam. Seoul was supposed to pick a winner in the FX III contest last fall, but the decision has been pushed back to mid-2013.

The famously over-budget and behind-schedule F-35 is meant to perform both air-to-air and ground-attack missions for the U.S. Air Force, Navy, Marines and the militaries of 10 other countries.

Boeing’s Silent Eagle is an upgraded version of its venerable F-15 Eagle/F-15E Strike Eagle, featuring V-shaped tails, internal weapons bays, and radar absorbent material in an effort to make it stealthy. Unveiled in 2009, the Silent Eagle is being offered by the Chicago-based company as a low-cost alternative to the F-35. It has no buyers yet, but South Korea’s Korean Aircraft Industries is teaming with Boeing to develop the F-15SE’s weapons bays.

The Korean air force already flies 60 F-15E Strike Eagles, known as F-15K SLAM Eagles due to their ability to carry SLAM-ER cruise missiles.

Still, the South Korean government has stated that it wants a modern stealth fighter such as the F-22 or the F-35 and even expressed interest in the Russian-made Sukhoi T-50 PAK FA stealth jet. While the F-15SE is stealthier than a regular F-15, it’s not as stealthy as a plane designed from the start to be stealthy.