With time running out, White House and Senate negotiators strained Sunday to find an agreement on US border security that would allow President Joe Biden’s request for billions of dollars in military aid for Ukraine and other national security requirements to be granted before senators left town for the holiday break. The Biden administration, which is getting increasingly active in the discussions, is under pressure from all parties to reach an agreement. Negotiators believe they are making progress, but no framework has emerged. Republican leaders said that an impending procedural vote would most likely fail in the absence of legislative...