 President Biden hosting a NATO summit starting Tuesday in Washington, where ABC's Perry Russom is. According to a senior Biden administration official, there will be a strong demonstration of support for Ukraine, reaffirming Ukraine's future is in NATO, with this being a part of the country's bridge to NATO. The U.S. is expected to announce new steps to strengthen Ukraine's air defenses. More affordable mortgages, ABC's Jim Ryan. Housing market experts say buyers can get rates as low as 3% from a home seller with an assumable mortgage.