On Wednesday, six Russian aircraft entered the United States' air defense identification zone (ADIZ), an area beyond sovereign U.S. airspace, according to a statement from NORAD, a U.S. and Canadian aerospace command, and U.S. Northern Command (NORTHCOM).
In response, "two Alaskan-based F-22 fighter jets acting under the authority of NORAD identified and intercepted two Russian IL-78 refueling tankers, two Russian Mig-31 fighter jets and two Russian Bear long-range bombers in the ADIZ, west of Alaska," the statement said.
On Thursday, Canadian fighter jets intercepted two Russian Bear long-range bombers in the Canadian ADIZ.
The Russian bombers did not enter the United States' or Canada's sovereign airspace.
John Cornelio, a spokesman for NORAD and NORTHCOM, said that such intercepts had happened over 50 times in the last five years as Russian aircraft conducted exercises.
"We do not see these flights as a threat," he said.
Ukrainian President Petro Poroshenko secured over $50 million in U.S. assistance during a visit to Washington this week but did not clinch U.S. weapons his soldiers might use to fight the separatists. Poroshenko also visited Canada this week and received aid in the form of a C$200 million ($182 million)five-year loan. (Reporting by Missy Ryan; Editing by Lisa Shumaker)